linux-phytec-fsl

drm: atmel-hlcdc: support asynchronous atomic commit operations

drm_atomic_helper_commit() does not support asynchronous commits.
Replace it by a specific commit function supporting these kind of requests.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Nicolas Ferre <nicolas.ferre@atmel.com>