drm/radeon/dce6: add missing display reg for tiling setup

A new tiling config register for the display blocks was
added on DCE6.

May fix:
https://bugs.freedesktop.org/show_bug.cgi?id=62889
https://bugs.freedesktop.org/show_bug.cgi?id=57919

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/radeon/sid.h b/drivers/gpu/drm/radeon/sid.h
index 23fc08f..f84cff0 100644
--- a/drivers/gpu/drm/radeon/sid.h
+++ b/drivers/gpu/drm/radeon/sid.h
@@ -65,6 +65,8 @@
 
 #define DMIF_ADDR_CONFIG  				0xBD4
 
+#define DMIF_ADDR_CALC  				0xC00
+
 #define	SRBM_STATUS				        0xE50
 #define		GRBM_RQ_PENDING 			(1 << 5)
 #define		VMC_BUSY 				(1 << 8)