drm/radeon: fix hdmi audio on DCE3.0/3.1 asics

commit 58d327da9721f7a0f6e46c8dfa5cc5546fd7078a upstream.

These asics seem to use a mix of the DCE2.x and
DCE3.2 audio interfaces despite what the register spec
says.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=69729
https://bugs.freedesktop.org/show_bug.cgi?id=69671



Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>