iommu/amd: Report SEV-TIO support

iommu/amd: Report SEV-TIO support

The SEV-TIO switch in the AMD BIOS is reported to the OS via
the IOMMU Extended Feature 2 register (EFR2), bit 1.

Add helper to parse the bit and report the feature presence.

Signed-off-by: Alexey Kardashevskiy <aik@amd.com>
Link: https://patch.msgid.link/20251202024449.542361-4-aik@amd.com
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>