drm/radeon/kms: add wait_for_vblank asic callback

Required for future functionality.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_reg.h b/drivers/gpu/drm/radeon/radeon_reg.h
index b4ce864..5098634 100644
--- a/drivers/gpu/drm/radeon/radeon_reg.h
+++ b/drivers/gpu/drm/radeon/radeon_reg.h
@@ -539,9 +539,11 @@
 
 #define RADEON_CRTC2_PITCH                  0x032c
 #define RADEON_CRTC_STATUS                  0x005c
+#       define RADEON_CRTC_VBLANK_CUR       (1 <<  0)
 #       define RADEON_CRTC_VBLANK_SAVE      (1 <<  1)
 #       define RADEON_CRTC_VBLANK_SAVE_CLEAR  (1 <<  1)
 #define RADEON_CRTC2_STATUS                  0x03fc
+#       define RADEON_CRTC2_VBLANK_CUR       (1 <<  0)
 #       define RADEON_CRTC2_VBLANK_SAVE      (1 <<  1)
 #       define RADEON_CRTC2_VBLANK_SAVE_CLEAR  (1 <<  1)
 #define RADEON_CRTC_V_SYNC_STRT_WID         0x020c