drm/i915/skl: drop workarounds for C0 revision

Pre-production hardware is not supported.
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/ed7b784306b35fa5215b9c04de79a2bc48585503.1474034059.git.jani.nikula@intel.com

drivers/gpu/drm/i915/intel_guc_loader.c

@@ -382,8 +382,7 @@ static int guc_ucode_xfer(struct drm_i915_private *dev_priv)
 	}
 
 	/* WaC6DisallowByGfxPause*/
-	if (IS_SKL_REVID(dev, 0, SKL_REVID_C0) ||
-	    IS_BXT_REVID(dev, 0, BXT_REVID_B0))
+	if (IS_BXT_REVID(dev, 0, BXT_REVID_B0))
 		I915_WRITE(GEN6_GFXPAUSE, 0x30FFF);
 
 	if (IS_BROXTON(dev))

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -882,9 +882,8 @@ static int gen9_init_workarounds(struct intel_engine_cs *engine)
 	WA_CLR_BIT_MASKED(GEN9_HALF_SLICE_CHICKEN5,
 			  GEN9_CCS_TLB_PREFETCH_ENABLE);
 
-	/* WaDisableMaskBasedCammingInRCC:skl,bxt */
-	if (IS_SKL_REVID(dev_priv, SKL_REVID_C0, SKL_REVID_C0) ||
-	    IS_BXT_REVID(dev_priv, 0, BXT_REVID_A1))
+	/* WaDisableMaskBasedCammingInRCC:bxt */
+	if (IS_BXT_REVID(dev_priv, 0, BXT_REVID_A1))
 		WA_SET_BIT_MASKED(SLICE_ECO_CHICKEN0,
 				  PIXEL_MASK_CAMMING_DISABLE);