x86: remove has_hvm_container_{domain/vcpu}

x86: remove has_hvm_container_{domain/vcpu}

It is now useless since PVHv1 is removed and PVHv2 is a HVM domain from Xen's
point of view.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>