dt-bindings: gpio: brcmstb: drop unneeded quotes

Drop unneeded quotes over simple string values to fix a soon to be
enabled yamllint warning:

[error] string value is redundantly quoted with any quotes (quoted-strings)

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

dt-bindings: gpio: Convert Broadcom STB GPIO to YAML

Convert the Broadcom STB GPIO Device Tree binding to YAML to help with
validation.

Acked-by: Gregory Fong <gregory.0xf0@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20211208003727.3596577-6-f.fainelli@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>