pinctrl: mediatek: add MT7988 pinctrl driver

Add pinctrl driver for the MediaTek MT7988 SoC.

Signed-off-by: Sam Shih <sam.shih@mediatek.com>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
[correctly initialise for the function_desc structure]
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.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/20241217085435.9586-3-linux@fw-web.de


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>