irqchip: mips-gic: Inline gic_basic_init()

gic_basic_init() is now a fairly short function that is only called in
one place. Inline it into gic_of_init() to help readability.

[ralf@linux-mips.org: Resolved conflict.]

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/17051/


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