drm/radeon: fix audio dto calculation on DCE3+ (v3)

Need to set the wallclock ratio and adjust the phase
and module registers appropriately.  May fix problems
with audio timing at certain display timings.

v2: properly handle clocks below 24mhz
v3: rebase r600 changes

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/evergreend.h b/drivers/gpu/drm/radeon/evergreend.h
index a7baf67..0d582ac 100644
--- a/drivers/gpu/drm/radeon/evergreend.h
+++ b/drivers/gpu/drm/radeon/evergreend.h
@@ -497,6 +497,9 @@
 #define DCCG_AUDIO_DTO0_MODULE            0x05b4
 #define DCCG_AUDIO_DTO0_LOAD              0x05b8
 #define DCCG_AUDIO_DTO0_CNTL              0x05bc
+#       define DCCG_AUDIO_DTO_WALLCLOCK_RATIO(x) (((x) & 7) << 0)
+#       define DCCG_AUDIO_DTO_WALLCLOCK_RATIO_MASK 7
+#       define DCCG_AUDIO_DTO_WALLCLOCK_RATIO_SHIFT 0
 
 #define DCCG_AUDIO_DTO1_PHASE             0x05c0
 #define DCCG_AUDIO_DTO1_MODULE            0x05c4