linux-imx

ptp_kvm: try to detect hypercall availability

No point in registering the device if it cannot work.
The hypercall does not advertise itself, so we have to call it.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>