dt-bindings: pwm: Add pwm-gpio

dt-bindings: pwm: Add pwm-gpio

Add bindings for PWM modulated by GPIO.

Signed-off-by: Nicola Di Lieto <nicola.dilieto@gmail.com>
Co-developed-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240604-pwm-gpio-v7-1-6b67cf60db92@linaro.org
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>