irqchip: mips-gic: Drop gic_(re)set_mask() functions

The gic_set_mask() & gic_reset_mask() functions are now no more
convenient to call than the write_gic_smask() or write_gic_rmask()
accessor functions. Remove the layer of abstraction.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17028/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>