drm/i915: WaRsDisableCoarsePowerGating

BugLink: http://bugs.launchpad.net/bugs/1527462

WaRsDisableCoarsePowerGating: Coarse Power Gating (CPG) needs to be
disabled for platforms prior to BXT B0 and SKL GT3/GT4 till E0.

v2: Added GT3/GT4 Check.

Change-Id: Ia3c4c16e050c88d3e259f601054875c812d69c3a
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: Alex Dai <yu.dai@intel.com>
[danvet: Align continuation properly.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

(back ported from commit f2d2fe95)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

Conflicts:
	drivers/gpu/drm/i915/intel_pm.c

drivers/gpu/drm/i915/intel_pm.c

@@ -4824,7 +4824,7 @@ static void gen9_enable_rc6(struct drm_device *dev)
 	 * WaRsDisableCoarsePowerGating:skl,bxt - Render/Media PG need to be disabled with RC6.
 	 */
 	if ((IS_BROXTON(dev) && (INTEL_REVID(dev) < BXT_REVID_B0)) ||
-	    ((IS_SKL_GT3(dev) || IS_SKL_GT4(dev)) && (INTEL_REVID(dev) <= SKL_REVID_F0)))
+	    ((IS_SKL_GT3(dev) || IS_SKL_GT4(dev)) && (INTEL_REVID(dev) <= SKL_REVID_E0)))
 		I915_WRITE(GEN9_PG_ENABLE, 0);
 	else
 		I915_WRITE(GEN9_PG_ENABLE, (rc6_mask & GEN6_RC_CTL_RC6_ENABLE) ?