staging/vc04_services: Register a platform device for the camera driver.

We had the camera driver set up in a module_init function, but that
meant that the camera driver would fail to load if it was initialized
before VCHI.  By attaching to this platform_device, it can get a
defined load order.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>