irqchip/mips-gic: Setup defaults in each cluster

In multi-cluster MIPS I6500 systems, there is a GIC per cluster.

The default shared interrupt setup configured in gic_of_init() applies only
to the GIC in the cluster containing the boot CPU, leaving the GICs of
other clusters unconfigured.

Configure the other clusters as well.

Signed-off-by: Chao-ying Fu <cfu@wavecomp.com>
Signed-off-by: Dragan Mladjenovic <dragan.mladjenovic@syrmia.com>
Signed-off-by: Aleksandar Rikalo <arikalo@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/all/20241028175935.51250-4-arikalo@gmail.com