dt-bindings: pinctrl: Drop unneeded quotes

dt-bindings: pinctrl: Drop unneeded quotes

Cleanup bindings dropping unneeded quotes. Once all these are fixed,
checking for this can be enabled in yamllint.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Hector Martin <marcan@marcan.st>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de> #rockchip
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230330200402.2731992-1-robh@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>