irqchip: Add Broadcom BCM2712 MSI-X interrupt controller

irqchip: Add Broadcom BCM2712 MSI-X interrupt controller

Add an interrupt controller driver for MSI-X Interrupt Peripheral (MIP)
hardware block found in BCM2712. The interrupt controller is used to
handle MSI-X interrupts from peripherials behind PCIe endpoints like
RPi1 south bridge found in RPi5.

There are two MIPs on BCM2712, the first has 64 consecutive SPIs
assigned to 64 output vectors, and the second has 17 SPIs, but only
8 of them are consecutive starting at the 8th output vector.

Signed-off-by: Stanimir Varbanov <svarbanov@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Ivan T. Ivanov <iivanov@suse.de>
Link: https://lore.kernel.org/r/20250224083559.47645-4-svarbanov@suse.de
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>