gma500/cdv: sync up and add the displayport code to the build

This is mostly just aligning bits of behaviour

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

diff --cc drivers/gpu/drm/gma500/Makefile
Simple merge

diff --cc drivers/gpu/drm/gma500/cdv_intel_display.c
Simple merge

diff --cc drivers/gpu/drm/gma500/cdv_intel_dp.c
Simple merge

diff --cc drivers/gpu/drm/gma500/psb_intel_drv.h
Simple merge