iommu/vt-d: Remove unused vcmd interfaces

Commit 99b5726b ("iommu: Remove ioasid infrastructure") has removed
ioasid allocation interfaces from the iommu subsystem. As a result, these
vcmd interfaces have become obsolete. Remove them to avoid dead code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20231116015048.29675-4-baolu.lu@linux.intel.com


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