irqchip/riscv-imsic: Add device MSI domain support for PCI devices

The Linux PCI framework supports per-device MSI domains for PCI devices
so extend the IMSIC driver to allow PCI per-device MSI domains.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20240307140307.646078-5-apatel@ventanamicro.com