libxc: expand cpuid features exposed to PVH guests

libxc: expand cpuid features exposed to PVH guests

Expand the cpuid features exposed to PVH guests, this includes
exposing PSE, PGE and 1GB pages (which will be masked by the
hypervisor if not supported by the hardware).

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>