irqchip: gic: Silence sparse warnings

drivers/irqchip/irq-gic.c:53:23: warning: duplicate [noderef]
drivers/irqchip/irq-gic.c:651:6: warning: symbol 'gic_raise_softirq' was not declared. Should it be static?
drivers/irqchip/irq-gic.c:872:29: warning: symbol 'gic_irq_domain_ops' was not declared. Should it be static?
drivers/irqchip/irq-gic.c:977:12: warning: symbol 'gic_of_init' was not declared. Should it be static?

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1393981321-25721-1-git-send-email-sboyd@codeaurora.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>