pinctrl: mediatek: extend advanced pull support in pinctrl-mtk-common-v2.c

Extend the advanced pull based on the legacy bias plus additional r0 and r1
to tweak the resistor level.

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>