metag: tz1090: select and instantiate pinctrl-tz1090

Select PINCTRL and PINCTRL_TZ1090 from SOC_TZ1090 to enable the main pin
controller driver once it is merged, and instantiate it from
tz1090.dtsi.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Grant Likely <grant.likely@linaro.org>