Declare 'audio-bus' clock for IISv4 controller of S3C6410.
Even though the name is same as that for IISv3, the id is
set to -1(just one instance of the controller is available)
which helps always fetch the correct clock.
Signed-off-by: Jassi Brar <jassi.brar@samsung.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>