irqchip/bcm7120-l2: Make probe functions static

The probe functions in this driver are not exported or declared
for use elsewhere, so make them static to fix the warnings:

drivers/irqchip/irq-bcm7120-l2.c:218:12: warning: symbol 'bcm7120_l2_intc_probe' was not declared. Should it be static?
drivers/irqchip/irq-bcm7120-l2.c:342:12: warning: symbol 'bcm7120_l2_intc_probe_7120' was not declared. Should it be static?
drivers/irqchip/irq-bcm7120-l2.c:349:12: warning: symbol 'bcm7120_l2_intc_probe_3380' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Link: https://lkml.kernel.org/r/1465408798-16201-1-git-send-email-ben.dooks@codethink.co.uk


Signed-off-by: Jason Cooper <jason@lakedaemon.net>