pinctrl: ralink: rename pinmux functions to pinctrl

Rename pinctrl related functions from "pinmux" to "pinctrl". Change driver
name from "ralink-pinmux" to "ralink-pinctrl".

Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Reviewed-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Acked-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20220414173916.5552-4-arinc.unal@arinc9.com


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