pinctrl: mediatek: add pull_type attribute for mediatek MT7986 SoC

pinctrl: mediatek: add pull_type attribute for mediatek MT7986 SoC

Commit fb34a9ae383a ("pinctrl: mediatek: support rsel feature")
add SoC specify 'pull_type' attribute for bias configuration.

This patch add pull_type attribute to pinctrl-mt7986.c, and make
bias_set_combo and bias_get_combo available to mediatek MT7986 SoC.

Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20221106080114.7426-7-linux@fw-web.de
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>