pinctrl: imx: Support NXP scmi extended mux config
i.MX94 has special muxing options for certain pins. Their mux settings
are not in IOMUXC module. i.MX System Manager Firmware includes new vendor
defined pinctrl type to SCMI pinctrl driver to handle these pins. The MUX
value field in the IOMUX table is extended to 16 bits where the lower 8
bits represent the current IOMUX value and the upper 8 bits represent the
new extended mux added in i.MX94.