ARM: 8368/1: sa1100: move irq driver to drivers/irqchip/

Move current sa11x0 IRQ driver to the irqchip subsystem.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>