gma500/cdv: add the bits that don't need the new code

Based on bits from Yakui <yakui.zhao@intel.com>

We can import various little bits of code before we plumb it all
in and hopefully this way catch any regressions more easily.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>