ARM: dts: nomadik: add accelerometer IRQ and pin setting

The LIS3LV02DL accelerometer on the Nomadik NHK15 can generate
IRQs by the DRDY line. Map this in the DTS file and set up the
pin as input to the SoC.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>