drm/imx: ipuv3-plane: use drm managed resources

Use drmm_universal_plane_alloc() to align plane memory lifetime with
the drm device. drm_plane_cleanup() is called automatically before the
memory is freed.
Also move the call to ipu_plane_get_resources() into ipu_plane_init()
and use drm managed resources to put IPU resources automatically when
required. Handle error return values of the plane property creation
functions.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>