x86/pv: Fix !CONFIG_PV build following XSA-299

x86/pv: Fix !CONFIG_PV build following XSA-299

PTF_* are declared within CONFIG_PV, and used outside:

  mm.c: In function ‘_put_page_type’:
  mm.c:2819:32: error: ‘PTF_preemptible’ undeclared (first use in this function)
       bool preemptible = flags & PTF_preemptible;
                                  ^~~~~~~~~~~~~~~
  mm.c:2819:32: note: each undeclared identifier is reported only once for each
  function it appears in
  mm.c:2842:24: error: ‘PTF_partial_set’ undeclared (first use in this function)
           if ( !(flags & PTF_partial_set) )
                          ^~~~~~~~~~~~~~~
  mm.c: In function ‘put_page_type_preemptible’:
  mm.c:3090:33: error: ‘PTF_preemptible’ undeclared (first use in this function)
       return _put_page_type(page, PTF_preemptible, NULL);
                                   ^~~~~~~~~~~~~~~
  mm.c: In function ‘put_old_guest_table’:
  mm.c:3108:25: error: ‘PTF_preemptible’ undeclared (first use in this function)
                           PTF_preemptible |
                           ^~~~~~~~~~~~~~~
  mm.c:3110:27: error: ‘PTF_partial_set’ undeclared (first use in this function)
                             PTF_partial_set : 0 ),
                             ^~~~~~~~~~~~~~~
  mm.c: In function ‘put_page_type_preemptible’:
  mm.c:3091:1: error: control reaches end of non-void function
  [-Werror=return-type]
   }
   ^
  cc1: all warnings being treated as errors

Re-position the definitions to be outside of the #ifdef CONFIG_PV

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wl@xen.org>
Release-acked-by: Juergen Gross <jgross@suse.com>