This bit is used to specify sdxc pinmap for mt76x8. Details available
in patch description.
To properly solve this problem and the other pinctrl hack in mtk-mmc
driver we'll need to write a dedicated pinctrl driver for mt76x8,
with the support for configuring AGPIO_MODE and RGCTL registers as
well as specially handling GPIO reservation/pinctrl setup for ESDMODE.
Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
