pinctrl: mediatek: Fix fallback call path

Some SoCs, eg. mt8183, are using a pinconfig operation bias_set_combo.
The fallback path in mtk_pinconf_adv_pull_set() should also try this
operation.

Fixes: cafe19d ("pinctrl: mediatek: Backward compatible to previous Mediatek's bias-pull usage")
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Acked-by: Sean Wang <sean.wang@kernel.org>
Link: https://lore.kernel.org/r/20201228090425.2130569-1-hsinyi@chromium.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c

@@ -920,6 +920,10 @@ int mtk_pinconf_adv_pull_set(struct mtk_pinctrl *hw,
 			err = hw->soc->bias_set(hw, desc, pullup);
 			if (err)
 				return err;
+		} else if (hw->soc->bias_set_combo) {
+			err = hw->soc->bias_set_combo(hw, desc, pullup, arg);
+			if (err)
+				return err;
 		} else {
 			return -ENOTSUPP;
 		}