PCI/MSI: Make the pci_msi_map_rid_ctlr_node() interface firmware agnostic

PCI/MSI: Make the pci_msi_map_rid_ctlr_node() interface firmware agnostic

To support booting with OF and ACPI seamlessly, GIC ITS parent code
requires the PCI/MSI irqdomain layer to implement a function to retrieve
an MSI controller fwnode and map an RID in a firmware agnostic way
(ie pci_msi_map_rid_ctlr_node()).

Convert pci_msi_map_rid_ctlr_node() to an OF agnostic interface
(fwnode_handle based) and update the GIC ITS MSI parent code to reflect
the pci_msi_map_rid_ctlr_node() change.

Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260115-gicv5-host-acpi-v3-2-c13a9a150388@kernel.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>