drm/radeon/kms: add support for semaphores v3

They are used to sync between rings, while fences
sync between a ring and the cpu.

v2 Fix radeon_semaphore_driver_fini when no semaphore were
allocated.

v3 Initialize list early on to avoid issue in case or early
error

Signed-off-by: Christian König <deathsimple@vodafone.de>
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/r600d.h b/drivers/gpu/drm/radeon/r600d.h
index bfe1b5d..3ee1fd7 100644
--- a/drivers/gpu/drm/radeon/r600d.h
+++ b/drivers/gpu/drm/radeon/r600d.h
@@ -831,6 +831,8 @@
 #define	PACKET3_STRMOUT_BUFFER_UPDATE			0x34
 #define	PACKET3_INDIRECT_BUFFER_MP			0x38
 #define	PACKET3_MEM_SEMAPHORE				0x39
+#              define PACKET3_SEM_SEL_SIGNAL	    (0x6 << 29)
+#              define PACKET3_SEM_SEL_WAIT	    (0x7 << 29)
 #define	PACKET3_MPEG_INDEX				0x3A
 #define	PACKET3_WAIT_REG_MEM				0x3C
 #define	PACKET3_MEM_WRITE				0x3D