dmaengine: stm32-mdma: fix PM reference leak in stm32_mdma_alloc_chan_resourc()

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: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20210517081826.1564698-2-yukuai3@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>