drm/radeon/audio: don't set speaker allocation on DCE3.2

It causes hangs on some asics.

Bug:
https://bugs.freedesktop.org/show_bug.cgi?id=70439



Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>