dt-bindings: input: bindings for Adafruit Seesaw Gamepad

dt-bindings: input: bindings for Adafruit Seesaw Gamepad

Adds bindings for the Adafruit Seesaw Gamepad.

The gamepad functions as an i2c device with the default address of 0x50
and has an IRQ pin that can be enabled in the driver to allow for a rising
edge trigger on each button press or joystick movement.

Product page:
  https://www.adafruit.com/product/5743
Arduino driver:
  https://github.com/adafruit/Adafruit_Seesaw

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Anshul Dalal <anshulusr@gmail.com>
Link: https://lore.kernel.org/r/20240106015111.882325-1-anshulusr@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>