iommufd: vfio compatibility extension check for noiommu mode

iommufd: vfio compatibility extension check for noiommu mode

VFIO_CHECK_EXTENSION should return false for TYPE1_IOMMU variants when
in NO-IOMMU mode and IOMMUFD compat container is set. This change makes
the behavior match VFIO_CONTAINER in noiommu mode. It also prevents
userspace from incorrectly attempting to use TYPE1 IOMMU operations
in a no-iommu context.

Fixes: d624d6652a65 ("iommufd: vfio container FD ioctl compatibility")
Link: https://patch.msgid.link/r/20260213183636.3340-1-jacob.pan@linux.microsoft.com
Signed-off-by: Jacob Pan <jacob.pan@linux.microsoft.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>