drm/i915/fbc: Clean up all register defines

The FBC register defines are a mess:
- namespace changes between DPFC_, FBC_, and some platform
  specific prefix at a whim
- ilk+ reuses most g4x bits but still has some separate bit
  defines elsewhere
- it's not clear from the defines that the bit defines are
  shared

So let's clean it up:
- both g4x and ilk register share the same defines now
- only defines which conflict have a _PLATFORM suffix, everyone
  else just gets comments to indicate which platforms do what
- namespace is consistent DPFC_ now
- SNB system agent fence registers also get a consistent namespace
- REG_BIT() & co. for everything

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211104144520.22605-13-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index cffb3df..2796f32 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -161,7 +161,7 @@ static void bxt_init_clock_gating(struct drm_i915_private *dev_priv)
 	 * Display WA #0883: bxt
 	 */
 	intel_uncore_write(&dev_priv->uncore, ILK_DPFC_CHICKEN, intel_uncore_read(&dev_priv->uncore, ILK_DPFC_CHICKEN) |
-		   ILK_DPFC_DISABLE_DUMMY0);
+		   DPFC_DISABLE_DUMMY0);
 }
 
 static void glk_init_clock_gating(struct drm_i915_private *dev_priv)
@@ -7435,7 +7435,7 @@ static void icl_init_clock_gating(struct drm_i915_private *dev_priv)
 {
 	/* Wa_1409120013:icl,ehl */
 	intel_uncore_write(&dev_priv->uncore, ILK_DPFC_CHICKEN,
-		   ILK_DPFC_CHICKEN_COMP_DUMMY_PIXEL);
+		   DPFC_CHICKEN_COMP_DUMMY_PIXEL);
 
 	/*Wa_14010594013:icl, ehl */
 	intel_uncore_rmw(&dev_priv->uncore, GEN8_CHICKEN_DCPR_1,
@@ -7448,7 +7448,7 @@ static void gen12lp_init_clock_gating(struct drm_i915_private *dev_priv)
 	if (IS_TIGERLAKE(dev_priv) || IS_ROCKETLAKE(dev_priv) ||
 	    IS_ALDERLAKE_S(dev_priv) || IS_DG1(dev_priv))
 		intel_uncore_write(&dev_priv->uncore, ILK_DPFC_CHICKEN,
-				   ILK_DPFC_CHICKEN_COMP_DUMMY_PIXEL);
+				   DPFC_CHICKEN_COMP_DUMMY_PIXEL);
 
 	/* Wa_1409825376:tgl (pre-prod)*/
 	if (IS_TGL_DISPLAY_STEP(dev_priv, STEP_A0, STEP_C0))
@@ -7510,7 +7510,7 @@ static void cfl_init_clock_gating(struct drm_i915_private *dev_priv)
 	 * Display WA #0873: cfl
 	 */
 	intel_uncore_write(&dev_priv->uncore, ILK_DPFC_CHICKEN, intel_uncore_read(&dev_priv->uncore, ILK_DPFC_CHICKEN) |
-		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
+		   DPFC_NUKE_ON_ANY_MODIFICATION);
 }
 
 static void kbl_init_clock_gating(struct drm_i915_private *dev_priv)
@@ -7543,7 +7543,7 @@ static void kbl_init_clock_gating(struct drm_i915_private *dev_priv)
 	 * Display WA #0873: kbl
 	 */
 	intel_uncore_write(&dev_priv->uncore, ILK_DPFC_CHICKEN, intel_uncore_read(&dev_priv->uncore, ILK_DPFC_CHICKEN) |
-		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
+		   DPFC_NUKE_ON_ANY_MODIFICATION);
 }
 
 static void skl_init_clock_gating(struct drm_i915_private *dev_priv)
@@ -7570,14 +7570,14 @@ static void skl_init_clock_gating(struct drm_i915_private *dev_priv)
 	 * Display WA #0873: skl
 	 */
 	intel_uncore_write(&dev_priv->uncore, ILK_DPFC_CHICKEN, intel_uncore_read(&dev_priv->uncore, ILK_DPFC_CHICKEN) |
-		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
+		   DPFC_NUKE_ON_ANY_MODIFICATION);
 
 	/*
 	 * WaFbcHighMemBwCorruptionAvoidance:skl
 	 * Display WA #0883: skl
 	 */
 	intel_uncore_write(&dev_priv->uncore, ILK_DPFC_CHICKEN, intel_uncore_read(&dev_priv->uncore, ILK_DPFC_CHICKEN) |
-		   ILK_DPFC_DISABLE_DUMMY0);
+		   DPFC_DISABLE_DUMMY0);
 }
 
 static void bdw_init_clock_gating(struct drm_i915_private *dev_priv)