drm: rcar-du: Fix PM reference leak in rcar_cmm_enable()

pm_runtime_get_sync will increment pm usage counter even it failed.
Forgetting to putting operation will result in a reference leak here.

A new function pm_runtime_resume_and_get is introduced in [0] to keep
usage counter balanced. So We fix the reference leak by replacing it
with new funtion.

[0] dd8088d5 ("PM: runtime: Add  pm_runtime_resume_and_get to deal with usage counter")

Fixes: e08e934d ("drm: rcar-du: Add support for CMM")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Acked-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>