pinctrl: mediatek: update pinmux definitions for mt6779

Add devicetree bindings for Mediatek mt6779 SoC Pin Controller.

Signed-off-by: Mars Cheng <[email protected]>
Signed-off-by: Andy Teng <[email protected]>
Signed-off-by: Hanks Chen <[email protected]>
Acked-by: Sean Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Linus Walleij <[email protected]>

Author: Hanks-Chen