dma: idxd: use DEFINE_MUTEX() for mutex lock

mainline inclusion
from mainline-v5.12
commit e2fcd6e4
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I596WO


CVE: NA

Intel-SIG: commit e2fcd6e4 dma: idxd: use DEFINE_MUTEX() for mutex lock.
Incremental backporting patches for DSA/IAA on Intel Xeon platform.

--------------------------------

mutex lock can be initialized automatically with DEFINE_MUTEX()
rather than explicitly calling mutex_init().

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20201224132254.30961-1-zhengyongjun3@huawei.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>