drm/i915: reorganize intel_lvds_supported

Now it returns false for all platforms unless they're explicitly
listed on the function. There should be no real difference, except for
the fact that it now returns false on Haswell.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_lvds.c

@@ -1020,15 +1020,15 @@ static bool intel_lvds_supported(struct drm_device *dev)
 {
 	/* With the introduction of the PCH we gained a dedicated
 	 * LVDS presence pin, use it. */
-	if (HAS_PCH_SPLIT(dev))
+	if (HAS_PCH_IBX(dev) || HAS_PCH_CPT(dev))
 		return true;
 
-	if (IS_VALLEYVIEW(dev))
-		return false;
-
 	/* Otherwise LVDS was only attached to mobile products,
 	 * except for the inglorious 830gm */
-	return IS_MOBILE(dev) && !IS_I830(dev);
+	if (INTEL_INFO(dev)->gen <= 4 && IS_MOBILE(dev) && !IS_I830(dev))
+		return true;
+
+	return false;
 }
 
 /**