irqchip/riscv-intc: Add ACPI support for AIA

irqchip/riscv-intc: Add ACPI support for AIA

The RINTC subtype structure in MADT also has information about other
interrupt controllers. Save this information and provide interfaces to
retrieve them when required by corresponding drivers.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20240812005929.113499-14-sunilvl@ventanamicro.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>