drm/radeon/evergreen: add indirect register accessors for CG registers

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/evergreen_reg.h b/drivers/gpu/drm/radeon/evergreen_reg.h
index 50948ac..76630c6b 100644
--- a/drivers/gpu/drm/radeon/evergreen_reg.h
+++ b/drivers/gpu/drm/radeon/evergreen_reg.h
@@ -44,6 +44,9 @@
 #define EVERGREEN_AUDIO_PLL1_DIV			0x5b4
 #define EVERGREEN_AUDIO_PLL1_UNK			0x5bc
 
+#define EVERGREEN_CG_IND_ADDR                           0x8f8
+#define EVERGREEN_CG_IND_DATA                           0x8fc
+
 #define EVERGREEN_AUDIO_ENABLE				0x5e78
 #define EVERGREEN_AUDIO_VENDOR_ID			0x5ec0