Revert "More audio use case enhacements"

This reverts commit 9fca36ce41e51bb3fbc0d0e065d41abc6fa1b88a.
Revert "d2: Update audio policy for new driver"

This reverts commit e7ecaaac0b74dbb80a535f1d931c487b5989d1f6.
Remove MDP 3 layer composition since it's not needed anymore.

Signed-off-by: Chuck Haines <chaines@codemonkeyjava.com>