[ARM] 3582/1: AT91RM9200 IRQ trigger types

Patch from Andrew Victor

The AIC interrupt controller's set_irq_type() can also be used for
internal interrupts.  IRQT_LOW and IRQT_FALLING are the only options not
supported for the internal interrupts.

[Original patch from Karl Olsen]

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>