The async name is deprecated and should be changed to nonblocking.

Also comments seem to be a bit outdated, as it looks like
nonblocking commit is supported by msm.

Cc: Rob Clark <robdclark@gmail.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461679905-30177-6-git-send-email-maarten.lankhorst@linux.intel.com