drm/mediatek: Fix PM reference leak in mtk_crtc_ddp_hw_init()

pm_runtime_get_sync will increment pm usage counter even it failed.
Forgetting to putting operation will result in reference leak here.
Fix it by replacing it with pm_runtime_resume_and_get to keep usage
counter balanced.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Li <wangli74@huawei.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>