[media] omap3isp: Report the ISP revision through the media controller API

Set the media_device::hw_revision field to the ISP revision number.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>