x86/hvm: change portio port numbers and sizes to unsigned int

x86/hvm: change portio port numbers and sizes to unsigned int

Building on the previous patch, this patch changes portio port numbers
and sizes to unsigned int which then allows the io_handler size field to
reduce to an unsigned int.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>