OSXAVE is not a static feature flag: it changes dynamically at
runtime depending on CR4, and it was never configurable: KVM
never returned OSXSAVE on GET_SUPPORTED_CPUID, and it is not
included in TCG_EXT_FEATURES.

Remove OSXSAVE from the feature name array so users don't try to
configure it manually.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Message-Id: <20180611203855.13269-1-ehabkost@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>