Merge tag 'fbdev-v4.11-rc6' of git://github.com/bzolnier/linux

Pull fbdev fixes from Bartlomiej Zolnierkiewicz:

 - fix probing time checks in omapfb driver (regression fix)

 - fix optional VBAT support in ssd1307fb driver (regression fix)

 - fix connecting to backend in xen-fbfront driver

* tag 'fbdev-v4.11-rc6' of git://github.com/bzolnier/linux:
  fbdev: omapfb: delete check_required_callbacks()
  xen, fbfront: fix connecting to backend
  fbdev/ssd1307fb: fix optional VBAT support