iommu/vt-d: Move capability check code to cap_audit files

Move IOMMU capability check and sanity check code to cap_audit files.
Also implement some helper functions for sanity checks.

Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210130184452.31711-1-kyung.min.park@intel.com
Link: https://lore.kernel.org/r/20210204014401.2846425-4-baolu.lu@linux.intel.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>