dt-bindings: Drop remaining unneeded quotes

Cleanup bindings dropping the last remaining unneeded quotes. With this,
the check for this can be enabled in yamllint.

Acked-by: Miquel Raynal <miquel.raynal@bootlin.com> # for mtd
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Wolfram Sang <wsa@kernel.org> # for AT24/I2C
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230823183749.2609013-1-robh@kernel.org


Signed-off-by: Rob Herring <robh@kernel.org>