Input: sa1111ps2 - use sa1111_get_irq() to obtain IRQ resources

Use the provided sa1111_get_irq() to fetch the IRQ resources for the
SA1111 PS/2 driver.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>