drm/amd/display: check if audio clk enable is applicable

Fixing warning on dce10 with HDMI display.

Signed-off-by: Roman Li <Roman.Li@amd.com>
Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>