drm/i915: Add IS_SKL_GT3 and IS_SKL_GT4 macro.

It will be usefull to specify w/a that affects only SKL GT3 and GT4.

Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: Alex Dai <yu.dai@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3795fdf..7cbc81f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2488,6 +2488,11 @@
 #define IS_SKL_ULX(dev)		(INTEL_DEVID(dev) == 0x190E || \
 				 INTEL_DEVID(dev) == 0x1915 || \
 				 INTEL_DEVID(dev) == 0x191E)
+#define IS_SKL_GT3(dev)		(IS_SKYLAKE(dev) && \
+				 (INTEL_DEVID(dev) & 0x00F0) == 0x0020)
+#define IS_SKL_GT4(dev)		(IS_SKYLAKE(dev) && \
+				 (INTEL_DEVID(dev) & 0x00F0) == 0x0030)
+
 #define IS_PRELIMINARY_HW(intel_info) ((intel_info)->is_preliminary)
 
 #define SKL_REVID_A0		(0x0)