drm/kernel: vblank wait on crtc > 1

drm/kernel: vblank wait on crtc > 1

Below is a patch against drm-next branch of 2.6.38-rc8+ kernel that adds
the capability to wait on vblank events for CRTCs that are greater than 1
and thus cannot be represented with primary/secondary flags in the legacy
interface. It was discussed on the dri-devel list in these two threads:

http://lists.freedesktop.org/archives/dri-devel/2011-March/009009.html
http://lists.freedesktop.org/archives/dri-devel/2011-March/009025.html

This patch extends the interface to drm_wait_vblank ioctl so that crtc>1
can be represented. It also adds a new capability to drm_getcap ioctl so
that the user space can check whether the new interface to drm_wait_vblank
is supported (and fall back to the legacy interface if not)

Signed-off-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
Reviewed-by: Mario Kleiner <mario.kleiner at tuebingen.mpg.de>
Acked-by: Mario Kleiner <mario.kleiner at tuebingen.mpg.de>
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Tested-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>