pinctrl: mediatek: add pinctrl-paris that implements the vendor dt-bindings

Add pinctrl-paris core that implements vendor dt-binding which MediaTek
tablet, box and smartphone-based SoCs such as MT81xx, MT27xx, and MT67xx
SoCs really want to depend on. The driver is just completely rewritten
according to pinctrl-mtk-common.c but uses the new logic from
pinctrl-mtk-common-v2.c to have an elegant way to support new SoCs in the
future.

Signed-off-by: Zhiyong Tao <zhiyong.tao@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>