This pull request introduces the vc4 driver, for kernel modesetting on
the Raspberry Pi (bcm2835/bcm2836 architectures).  It currently
supports a display plane and cursor on the HDMI output.  The driver
doesn't do 3D, power management, or overlay planes yet.

[airlied: fixup the enable/disable vblank APIs]
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

* tag 'drm-vc4-next-2015-10-21' of http://github.com/anholt/linux:
  drm/vc4: Allow vblank to be disabled
  drm/vc4: Use the fbdev_cma helpers
  drm/vc4: Add KMS support for Raspberry Pi.
  drm/vc4: Add devicetree bindings for VC4.