dt-bindings: pinctrl: fsl,imx6ul-pinctrl: Convert i.MX35/5x/6 to YAML

dt-bindings: pinctrl: fsl,imx6ul-pinctrl: Convert i.MX35/5x/6 to YAML

The IOMUXC controller description is almost identical on i.MX35/5x/6 SoCs,
except for the configuration bits which differ across SoCs. Rename the
fsl,imx6ul-pinctrl.yaml to fsl,imx35-pinctrl.yaml, fill in compatible
strings for the other SoCs and fill in the various bits into desciption.
This way, i.MX35/5x/6 series SoCs can all be converted to DT schema.
Remove the old text DT bindings description.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/20241017211241.170861-1-marex@denx.de
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>