OMAPDSS: switch FBIO_WAITFORVSYNC to the new code

Same as OMAPFB_WAITFORVSYNC_FRAME from previous commit, just without the
adaptive part. The benefits are:
- no unnecessary irq reprogramming before/after each wait
- fbdev lock release on wait so that multiple programs can wait
- better display detection when the output is cloned to multiple
  displays and one of them goes off

diff --cc drivers/video/omap2/omapfb/omapfb-ioctl.c
Simple merge