drm/radeon/kms: add some missing semaphore init

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/evergreend.h b/drivers/gpu/drm/radeon/evergreend.h
index b502216..74713d4 100644
--- a/drivers/gpu/drm/radeon/evergreend.h
+++ b/drivers/gpu/drm/radeon/evergreend.h
@@ -108,6 +108,7 @@
 #define	CP_RB_WPTR_ADDR_HI				0xC11C
 #define	CP_RB_WPTR_DELAY				0x8704
 #define	CP_SEM_WAIT_TIMER				0x85BC
+#define	CP_SEM_INCOMPLETE_TIMER_CNTL			0x85C8
 #define	CP_DEBUG					0xC1FC