drm/i915: Clean up the .get_cdclk() assignment if ladder

Let's clean up the mess we have in the if ladder that assigns the
.get_cdclk() hooks. The grouping of the platforms by the function
results in a thing that's not really legible, so let's do it the
other way around and order the if ladder by platform and duplicate
whatever assignments we need.

To further avoid confusion with the function names let's rename
them to just fixed_<freq>_get_cdclk(). The other option would
be to duplicate the functions entirely but it seems quite
pointless to do that since each one just returns a fixed value.

v2: Deal with i945gm_get_cdclk()
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170207183226.19537-1-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/intel_display.c

@@ -7385,12 +7385,12 @@ static int valleyview_get_cdclk(struct drm_i915_private *dev_priv)
 				      CCK_DISPLAY_CLOCK_CONTROL);
 }
 
-static int ilk_get_cdclk(struct drm_i915_private *dev_priv)
+static int fixed_450mhz_get_cdclk(struct drm_i915_private *dev_priv)
 {
 	return 450000;
 }
 
-static int i945_get_cdclk(struct drm_i915_private *dev_priv)
+static int fixed_400mhz_get_cdclk(struct drm_i915_private *dev_priv)
 {
 	return 400000;
 }
@@ -7415,12 +7415,12 @@ static int i945gm_get_cdclk(struct drm_i915_private *dev_priv)
 	}
 }
 
-static int i915_get_cdclk(struct drm_i915_private *dev_priv)
+static int fixed_333mhz_get_cdclk(struct drm_i915_private *dev_priv)
 {
 	return 333333;
 }
 
-static int i9xx_misc_get_cdclk(struct drm_i915_private *dev_priv)
+static int fixed_200mhz_get_cdclk(struct drm_i915_private *dev_priv)
 {
 	return 200000;
 }
@@ -7470,7 +7470,7 @@ static int i915gm_get_cdclk(struct drm_i915_private *dev_priv)
 	}
 }
 
-static int i865_get_cdclk(struct drm_i915_private *dev_priv)
+static int fixed_266mhz_get_cdclk(struct drm_i915_private *dev_priv)
 {
 	return 266667;
 }
@@ -7513,7 +7513,7 @@ static int i85x_get_cdclk(struct drm_i915_private *dev_priv)
 	return 0;
 }
 
-static int i830_get_cdclk(struct drm_i915_private *dev_priv)
+static int fixed_133mhz_get_cdclk(struct drm_i915_private *dev_priv)
 {
 	return 133333;
 }
@@ -16249,34 +16249,39 @@ void intel_init_display_hooks(struct drm_i915_private *dev_priv)
 		dev_priv->display.get_cdclk = haswell_get_cdclk;
 	else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
 		dev_priv->display.get_cdclk = valleyview_get_cdclk;
+	else if (IS_GEN6(dev_priv) || IS_IVYBRIDGE(dev_priv))
+		dev_priv->display.get_cdclk = fixed_400mhz_get_cdclk;
 	else if (IS_GEN5(dev_priv))
-		dev_priv->display.get_cdclk = ilk_get_cdclk;
-	else if (IS_I945G(dev_priv) || IS_I965G(dev_priv) ||
-		 IS_GEN6(dev_priv) || IS_IVYBRIDGE(dev_priv))
-		dev_priv->display.get_cdclk = i945_get_cdclk;
+		dev_priv->display.get_cdclk = fixed_450mhz_get_cdclk;
 	else if (IS_GM45(dev_priv))
 		dev_priv->display.get_cdclk = gm45_get_cdclk;
+	else if (IS_G4X(dev_priv))
+		dev_priv->display.get_cdclk = g33_get_cdclk;
 	else if (IS_I965GM(dev_priv))
 		dev_priv->display.get_cdclk = i965gm_get_cdclk;
+	else if (IS_I965G(dev_priv))
+		dev_priv->display.get_cdclk = fixed_400mhz_get_cdclk;
 	else if (IS_PINEVIEW(dev_priv))
 		dev_priv->display.get_cdclk = pnv_get_cdclk;
-	else if (IS_G33(dev_priv) || IS_G4X(dev_priv))
+	else if (IS_G33(dev_priv))
 		dev_priv->display.get_cdclk = g33_get_cdclk;
-	else if (IS_I915G(dev_priv))
-		dev_priv->display.get_cdclk = i915_get_cdclk;
-	else if (IS_I845G(dev_priv))
-		dev_priv->display.get_cdclk = i9xx_misc_get_cdclk;
 	else if (IS_I945GM(dev_priv))
 		dev_priv->display.get_cdclk = i945gm_get_cdclk;
+	else if (IS_I945G(dev_priv))
+		dev_priv->display.get_cdclk = fixed_400mhz_get_cdclk;
 	else if (IS_I915GM(dev_priv))
 		dev_priv->display.get_cdclk = i915gm_get_cdclk;
+	else if (IS_I915G(dev_priv))
+		dev_priv->display.get_cdclk = fixed_333mhz_get_cdclk;
 	else if (IS_I865G(dev_priv))
-		dev_priv->display.get_cdclk = i865_get_cdclk;
+		dev_priv->display.get_cdclk = fixed_266mhz_get_cdclk;
 	else if (IS_I85X(dev_priv))
 		dev_priv->display.get_cdclk = i85x_get_cdclk;
+	else  if (IS_I845G(dev_priv))
+		dev_priv->display.get_cdclk = fixed_200mhz_get_cdclk;
 	else { /* 830 */
 		WARN(!IS_I830(dev_priv), "Unknown platform. Assuming 133 MHz CDCLK\n");
-		dev_priv->display.get_cdclk = i830_get_cdclk;
+		dev_priv->display.get_cdclk = fixed_133mhz_get_cdclk;
 	}
 
 	if (IS_GEN5(dev_priv)) {