fix commit xen/arm: Add support for GICv3 for domU

fix commit xen/arm: Add support for GICv3 for domU

The build of xen-4.5.0-rc2 fails if XSM_ENABLE=y due to an inconsistency
in commit fda1614 "xen/arm: Add support for GICv3 for domU" which uses
XEN_DOMCTL_configure_domain in xen/xsm/flask/hooks.c and
xen/xsm/flask/policy/access_vectors but XEN_DOMCTL_arm_configure_domain
elsewhere.

 	Michael Young
In fda1614 ("xen/arm: Add support for GICv3 for domU")
XEN_DOMCTL_configure_domain is used in xen/xsm/flask/hooks.c and
xen/xsm/flask/policy/access_vectors but XEN_DOMCTL_arm_configure_domain
is used elsewhere.

Signed-off-by: Michael Young <m.a.young@durham.ac.uk>
Acked-by: Ian Campbell <ian.campbell@citrix.com>