ARM: 8232/1: sa1100: merge GPIO multiplexer IRQ to "normal" irq domain

IRQ_GPIO11_27 is a shared IRQ receiving IRQs from "high" GPIOs. It is
still handled by sa1100_normal_chip, so there is no point to exclude it
from "normal" irq domain. The IRQF_VALID flag set by domain map function
will be cleared by irq_set_chained_handler() internally.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>