drm/radeon/si: fix define for MC_SEQ_TRAIN_WAKEUP_CNTL

Typo in the register offset.
Noticed-by: Sylvain BERTRAND <sylware@legeek.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

drivers/gpu/drm/radeon/sid.h

@@ -478,7 +478,7 @@
 #define		STATE3_MASK				(0x1f << 15)
 #define		STATE3_SHIFT				15
 
-#define	MC_SEQ_TRAIN_WAKEUP_CNTL			0x2808
+#define	MC_SEQ_TRAIN_WAKEUP_CNTL			0x28e8
 #define		TRAIN_DONE_D0      			(1 << 30)
 #define		TRAIN_DONE_D1      			(1 << 31)