irqchip: digicolor: Move digicolor_set_gc to init section

The digicolor_set_gc() routine is only called from __init annotated
digicolor_of_init(). Annotate digicolor_set_gc() with __init as well to save a
few bytes at run time.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Link: https://lkml.kernel.org/r/a3b57ecdbe0b07f55c20c07ff98f1f694275722d.1427009985.git.baruch@tkos.co.ilSigned-off-by: Jason Cooper <jason@lakedaemon.net>

drivers/irqchip/irq-digicolor.c

@@ -55,8 +55,8 @@ static void __exception_irq_entry digicolor_handle_irq(struct pt_regs *regs)
 	} while (1);
 }
 
-static void digicolor_set_gc(void __iomem *reg_base, unsigned irq_base,
-			     unsigned en_reg, unsigned ack_reg)
+static void __init digicolor_set_gc(void __iomem *reg_base, unsigned irq_base,
+				    unsigned en_reg, unsigned ack_reg)
 {
 	struct irq_chip_generic *gc;