pinctrl/nomadik: pass DT node to the irqdomain

When creating the simple irqdomain, pass the DT node pointer along,
as is apropriate.

Acked-by: Lee Jones <lee.jones@linaro.org>
Reported-by: Gabriel Fernandez <gabriel.fernandez@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>