drm/i915/dg2: Drop pre-production display workarounds

All production DG2 cards have display stepping C0 or later.  We can drop
Wa_14013215631 (only applies to pre-C0) and make Wa_14010547955
unconditional (applies to everything B0 and beyond).  Also drop the
now-unused IS_DG2_DISPLAY_STEP macro.

Bspec: 44477
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230816214201.534095-9-matthew.d.roper@intel.com

drivers/gpu/drm/i915/display/intel_display.c

@@ -726,7 +726,7 @@ static void icl_set_pipe_chicken(const struct intel_crtc_state *crtc_state)
 		tmp |= UNDERRUN_RECOVERY_DISABLE_ADLP;
 
 	/* Wa_14010547955:dg2 */
-	if (IS_DG2_DISPLAY_STEP(dev_priv, STEP_B0, STEP_FOREVER))
+	if (IS_DG2(dev_priv))
 		tmp |= DG2_RENDER_CCSTAG_4_3_EN;
 
 	intel_de_write(dev_priv, PIPE_CHICKEN(pipe), tmp);

drivers/gpu/drm/i915/display/skl_universal_plane.c

@@ -2203,10 +2203,6 @@ static bool gen12_plane_has_mc_ccs(struct drm_i915_private *i915,
 	if (IS_ALDERLAKE_P(i915) && IS_DISPLAY_STEP(i915, STEP_A0, STEP_B0))
 		return false;
 
-	/* Wa_14013215631 */
-	if (IS_DG2_DISPLAY_STEP(i915, STEP_A0, STEP_C0))
-		return false;
-
 	return plane_id < PLANE_SPRITE4;
 }
 

drivers/gpu/drm/i915/i915_drv.h

@@ -689,10 +689,6 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915,
 	(IS_SUBPLATFORM(__i915, INTEL_DG2, INTEL_SUBPLATFORM_##variant) && \
 	 IS_GRAPHICS_STEP(__i915, since, until))
 
-#define IS_DG2_DISPLAY_STEP(__i915, since, until) \
-	(IS_DG2(__i915) && \
-	 IS_DISPLAY_STEP(__i915, since, until))
-
 #define IS_PVC_BD_STEP(__i915, since, until) \
 	(IS_PONTEVECCHIO(__i915) && \
 	 IS_BASEDIE_STEP(__i915, since, until))