pinctrl/lantiq: fix pinconfig parameters

The Falcon driver only defined the pinconf parameters but
did not pass them properly to the underlying api.

Signed-off-by: Thomas Langer <thomas.langer@lantiq.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>