Reapply "drm/i915: Pass atomic states to fbc update, functions."

Reapply "drm/i915: Pass atomic states to fbc update, functions."

The patch was reverted as part of the original nonblocking commit
support, but is required for any kind of nonblocking commit.

This is required to let fbc updates run async. It has a lot of
checks whether certain locks are taken, which can be removed when
the relevant states are passed in as pointers.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463490484-19540-17-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/28208c38-8738-abdf-0cce-8d8f266b9c28@linux.intel.com