drm/msm: remove unused define

Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/msm_drv.h

@@ -55,8 +55,6 @@ struct msm_fence_cb;
 struct msm_gem_address_space;
 struct msm_gem_vma;
 
-#define NUM_DOMAINS 2    /* one for KMS, then one per gpu core (?) */
-
 struct msm_file_private {
 	/* currently we don't do anything useful with this.. but when
 	 * per-context address spaces are supported we'd keep track of