MFC r340602:

MFC r340602:

gitv3_its: fixes for multiple GIC ITS blocks

First pass of support for multiple GIC ITS blocks with ACPI.
Changes are to:
 * register the correct subset of interrupts with pic_register
   in case of ACPI.
 * initialize just the cpu interface for the first ITS, when
   domain information is not avialable. This has to be done
   until we split the per-CPU init to do LPI setup just once.
 * remove duplicate check for the GIC ITS domain, the sc_cpus
   are setup from domain, so the check again in per-CPU init
   seems unnecessary.

Reviewed by:	andrew
Differential Revision:	https://reviews.freebsd.org/D17841