pinctrl: Add DT bindings for Toshiba Visconti TMPV7700 SoC

Add pinctrl bindings for Toshiba Visconti TMPV7700 SoC series.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Reviewed-by: Punit Agrawal <punit1.agrawal@toshiba.co.jp>
Link: https://lore.kernel.org/r/20200909204336.2558-2-nobuhiro1.iwamatsu@toshiba.co.jp


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