drm/i915: Add IS_BDW_GT3 macro.

It will be usefull to specify w/a that affects only BDW GT3.
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -2111,6 +2111,8 @@ struct drm_i915_cmd_table {
 				 ((INTEL_DEVID(dev) & 0xf) == 0x2  || \
 				 (INTEL_DEVID(dev) & 0xf) == 0x6 || \
 				 (INTEL_DEVID(dev) & 0xf) == 0xe))
+#define IS_BDW_GT3(dev)		(IS_BROADWELL(dev) && \
+				 (INTEL_DEVID(dev) & 0x00F0) == 0x0020)
 #define IS_HSW_ULT(dev)		(IS_HASWELL(dev) && \
 				 (INTEL_DEVID(dev) & 0xFF00) == 0x0A00)
 #define IS_ULT(dev)		(IS_HSW_ULT(dev) || IS_BDW_ULT(dev))