The STK1160 needs some time to transfer data to and from the AC97 codec.
The transfer completion is indicated by command read/write bits in the
chip's audio control register. The driver should poll these bits and
wait until they have been cleared by hardware before trying to retrieve
the results of a read operation or setting a new write command.

[mchehab@s-opensource.com: make checkpatch happier]
Signed-off-by: Marcel Hasler <mahasler@gmail.com>
Acked-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>