genirq/irqdomain: Reroute device MSI create_mapping

Reroute interrupt allocation in irq_create_fwspec_mapping() if the domain
is a MSI device domain. This is required to convert the support for wire
to MSI bridges to per device MSI domains.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240127161753.114685-13-apatel@ventanamicro.com