Add new emmc groups in the pinctrl driver for the
MediaTek MT7981 SoC:
* emmc reset, with pin 15.
* emmc 4-bit bus-width, with pins 16 to 19, and 24 to 25.
* emmc 8-bit bus-width, with pins 16 to 25.
The existing emmc_45 group is kept for legacy reasons, even
if this is the union of emmc_reset and emmc_8 groups.
Signed-off-by: Jean Thomas <jean.thomas@wifirst.fr>
