The sirfsoc_irqchip_to_bank() is obviously misnamed, as it is
not converting an irqchip to a bank but converts a gpiochip
to a bank so rename it sirfsoc_gpiochip_to_bank().
Acked-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>