IRQCHIP: irq-mips-gic: Add support for CM3 64-bit timer irqs

IRQCHIP: irq-mips-gic: Add support for CM3 64-bit timer irqs

CM3 uses a 64-bit counter and compare registers so add support for
them in the GIC counter interrupt.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10648/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>