[media] au8522: fix regression in logging introduced by separation of modules

The au8522 driver was broken into three modules (dig, decoder, common),
and as a result the debug modprobe option doesn't work for any of the
common functions.

Copy the module macros over to the common module so that the debug
option works again.

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>