[media] siano: use do_div() for 64-bits division

As reported by Frank Schäfer <fschaefer.oss@googlemail.com>:
	ERROR: "__divdi3" [drivers/media/common/siano/smsdvb.ko] undefined!

Reported-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Tested-by: Gianluca Gennari <gennarone@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>