This is needed for supporting the upcoming VX855 camera and OLPC DCON
drivers, as well as the advanced viafb features on non-OLPC hardware
based on this chip.

Based on earlier work by Harald Welte.
Signed-off-by: NDaniel Drake <dsd@laptop.org>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>