Merge tag 'drm-intel-fixes-2018-05-17' of git://anongit.freedesktop.org/drm/drm-intel...

- Userptr IOCTL zero size check (Matt)
- Two hardware quirk fixes (Michel & Chris)

* tag 'drm-intel-fixes-2018-05-17' of git://anongit.freedesktop.org/drm/drm-intel:
  drm/i915/gen9: Add WaClearHIZ_WM_CHICKEN3 for bxt and glk
  drm/i915/execlists: Use rmb() to order CSB reads
  drm/i915/userptr: reject zero user_size