KVM: selftests: Check that XTILEDATA supports XFD

Check that XTILEDATA supports XFD. In amx_test, add the requirement that
the guest allows the xfeature, XTILEDATA, to be set in XFD. Otherwise, the
test may fail.

Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20230221163655.920289-14-mizhang@google.com


Signed-off-by: Sean Christopherson <seanjc@google.com>