public/domctl: drop unnecessary typedefs and handles

public/domctl: drop unnecessary typedefs and handles

By virtue of the struct xen_domctl container structure, most of them
are really just cluttering the name space.

While doing so,
- convert an enum typed (pt_irq_type_t) structure field to a fixed
  width type,
- make x86's paging_domctl() and descendants take a properly typed
  handle,
- add const in a few places.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Acked-by: Dario Faggioli <dario.faggioli@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Meng Xu <mengxu@cis.upenn.edu>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Julien Grall <julien.grall@arm.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Tamas K Lengyel <tamas@tklengyel.com>