This adds a driver for the AW9523 I2C GPIO expander.
This driver is required to make LEDs as well as buttons on the Tenbay
T-MB5EU-V01 work.
This driver already had several upstream iterations. I'm working to
push this driver to mainline.
Ref: https://patchwork.ozlabs.org/project/linux-gpio/list/?series=226287
Signed-off-by: David Bauer <mail@david-bauer.net>
