The g_reg and s_reg calls worked properly if acting on subdev registers
(such as the au8522), but didn't work against the au0828 itself.  Copy
the logic over from em28xx.
Signed-off-by: NDevin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>