Parse named nodes from IORT ACPI on arm64

Add the ability to map named components from IORT to their
SMMU or ITS node in order to setup interrupts.
It is now possible to find a node by its name (substring) and
resource ID similar to PCI nodes.
This is needed by work on a driver for NXP's Second Generation
Data Path Acceleration Architecture (DPAA2).

Reviewed by: andrew
MFC after: 2 weeks
Differential Revision:: https://reviews.freebsd.org/D31267