[ARM] 4976/1: zylonite: Configure GPIO for WM9713 IRQ line

Set up the IRQ line for the WM9713 device on the Zylonite.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: eric miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>