dmaengine: idxd: remove bus shutdown

mainline inclusion
from mainline-v5.15
commit 3a5cc016
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I596WO


CVE: NA

Intel-SIG: commit 3a5cc016 dmaengine: idxd: remove bus shutdown.
Incremental backporting patches for DSA/IAA on Intel Xeon platform.

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

Remove ->shutdown() function for the dsa bus as it does not do anything and
is not necessary.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162637462319.744545.10383189484257042066.stgit@djiang5-desk3.ch.intel.com


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