HD interface and AC97 interface share some pins and they are enabled at
the same time, In order to use AC97 interface, we need to disable the HD
interface first.

Signed-off-by:Jason Jin<jason.jin@freescale.com>
Acked-by: Jon Loeliger <jdl@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>