drm/radeon: Fix "slow" audio over DP on DCE8+

DP audio is derived from the dfs clock.

Signed-off-by: Slava Grigorev <slava.grigorev@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
4 files changed