x86: remove PVHv1 code

x86: remove PVHv1 code

This removal applies to both the hypervisor and the toolstack side of PVHv1.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Razvan Cojocaru <rcojocaru@bitdefender.com>