The Armada overlay plane wasn't being properly cleaned up as it was
missing a call to drm_plane_cleanup().  It also wasn't freeing the
right type of pointer (although we were still freeing the right
pointer value.)
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Nothing was waking up the overlay plane wait queue, so we were fully
reliant on the HZ/25 wait timing out to make progress.  Fix the lack
of wake-up.

We were also mis-handling the wait_event_timeout() return value - this
returns an unsigned integer of the remaining time, or zero on timeout
and the condition evaluated false.  Checking this for less than zero
is not sane.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch adds support for the pair of LCD controllers on the Marvell
Armada 510 SoCs.  This driver supports:
- multiple contiguous scanout buffers for video and graphics
- shm backed cacheable buffer objects for X pixmaps for Vivante GPU
  acceleration
- dual lcd0 and lcd1 crt operation
- video overlay on each LCD crt via DRM planes
- page flipping of the main scanout buffers
- DRM prime for buffer export/import

This driver is trivial to extend to other Armada SoCs.

Included in this commit is the core driver with no output support; output
support is platform and encoder driver dependent.
Tested-by: NSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>