KVM: selftests: arm64: Add support for VM_MODE_P36V48_{4K,64K}

Some of the arm64 systems out there have an IPA space that is
positively tiny. Nonetheless, they make great KVM hosts.

Add support for 36bit IPA support with 4kB pages, which makes
some of the fruity machines happy. Whilst we're at it, add support
for 64kB pages as well, though these boxes have no support for it.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211227124809.1335409-6-maz@kernel.org