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.il


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