drm/radeon: fix audio pin counts for DCE6+ (v2)

There is actually quite a bit of variance based on
the asic.

v2: fix typo noticed by Jerome.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org