drm/i915: add platform tag to WA

v2: add more missing platform tags
v3: change tag to cnp rather than using gen9,gen10

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171205190118.7088-2-lucas.demarchi@intel.com

drivers/gpu/drm/i915/intel_hdmi.c

@@ -1380,7 +1380,7 @@ static bool hdmi_12bpc_possible(const struct intel_crtc_state *crtc_state)
 		}
 	}
 
-	/* Display WA #1139 */
+	/* Display WA #1139: glk */
 	if (IS_GLK_REVID(dev_priv, 0, GLK_REVID_A1) &&
 	    crtc_state->base.adjusted_mode.htotal > 5460)
 		return false;

drivers/gpu/drm/i915/intel_pm.c

@@ -8417,7 +8417,7 @@ static void cnp_init_clock_gating(struct drm_i915_private *dev_priv)
 	if (!HAS_PCH_CNP(dev_priv))
 		return;
 
-	/* Display WA #1181 */
+	/* Display WA #1181: cnp */
 	I915_WRITE(SOUTH_DSPCLK_GATE_D, I915_READ(SOUTH_DSPCLK_GATE_D) |
 		   CNP_PWM_CGE_GATING_DISABLE);
 }