irqchip/brcmstb-l2: Make of probe function static

The probe functions in this driver is not exported or declared
so make it static to fix the following warning:

drivers/irqchip/irq-brcmstb-l2.c:115:12: warning: symbol 'brcmstb_l2_intc_of_init' was not declared. Should it be static?

Signed-off-by: Ben Dooks <[e-mail]>
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Jason Cooper <[e-mail]>

drivers/irqchip/irq-brcmstb-l2.c

···
 	irq_gc_unlock(gc);
 }
 
-int __init brcmstb_l2_intc_of_init(struct device_node *np,
-					struct device_node *parent)
+static int __init brcmstb_l2_intc_of_init(struct device_node *np,
+					  struct device_node *parent)
 {
 	unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
 	struct brcmstb_l2_intc_data *data;