iommu/vt-d: Clean up unused PASID updating functions

mainline inclusion
from mainline-v5.16
commit 00ecd540
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I596WO


CVE: NA

Intel-SIG: commit 00ecd540 iommu/vt-d: Clean up unused PASID updating functions.
Incremental backporting patches for DSA/IAA on Intel Xeon platform.

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

update_pasid() and its call chain are currently unused in the tree because
Thomas disabled the ENQCMD feature. The feature will be re-enabled shortly
using a different approach and update_pasid() and its call chain will not
be used in the new approach.

Remove the useless functions.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20210920192349.2602141-1-fenghua.yu@intel.com


Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20211014053839.727419-8-baolu.lu@linux.intel.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>