Allow the i2c-mux-gpio to be used by a device tree enabled device. The
bindings are inspired by the one found in the i2c-mux-pinctrl driver.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NPeter Korsgaard <peter.korsgaard@barco.com>

[wsa: fixed some whitespace]
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>