drm/i915: Add references to some workaround we implement

We did not mention the workaround name when implementing those. This
should help us track what we already implement.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index d0c5ecf..f5523a8 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4125,8 +4125,8 @@
 	if (!pipe_config->timings_set)
 		drm_mode_set_crtcinfo(adjusted_mode, 0);
 
-	/* WaPruneModeWithIncorrectHsyncOffset: Cantiga+ cannot handle modes
-	 * with a hsync front porch of 0.
+	/* Cantiga+ cannot handle modes with a hsync front porch of 0.
+	 * WaPruneModeWithIncorrectHsyncOffset:ctg,elk,ilk,snb,ivb,vlv,hsw.
 	 */
 	if ((INTEL_INFO(dev)->gen > 4 || IS_G4X(dev)) &&
 		adjusted_mode->hsync_start == adjusted_mode->hdisplay)