libxc: fix the types used in xc_dom_image to build HVM guests

libxc: fix the types used in xc_dom_image to build HVM guests

Fix the types used to store the memory parameters of an HVM guest,
previously they defaulted to unsigned long on 32bit toolstack builds, which
is wrong because a 32bit value cannot hold a 64bit memory address that
crosses the 4GB boundary.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>