x86/pv: Prune include lists

x86/pv: Prune include lists

Several of these in particular haven't been pruned since the logic was all
part of arch/x86/traps.c

Some adjustments to header files are required to avoid compile errors:
 * emulate.h needs xen/sched.h because gdt_ldt_desc_ptr() uses v->vcpu_id.
 * mmconfig.h needs to forward declare acpi_table_header.
 * shadow.h and trace.h need to have uint*_t in scope before including the Xen
   public headers.  For shadow.h, reorder the includes.  For trace.h, include
   types.h

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>