i2c: core: add generic I2C GPIO recovery

i2c: core: add generic I2C GPIO recovery

Multiple I2C bus drivers use similar bindings to obtain information needed
for I2C recovery. For example, for platforms using device-tree, the
properties look something like this:

&i2c {
	...
	pinctrl-names = "default", "gpio";
	pinctrl-0 = <&pinctrl_i2c_default>;
	pinctrl-1 = <&pinctrl_i2c_gpio>;
	sda-gpios = <&pio 0 GPIO_ACTIVE_HIGH>;
	scl-gpios = <&pio 1 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
	...
}

For this reason, we can add this common initialization in the core. This
way, other I2C bus drivers will be able to support GPIO recovery just by
providing a pointer to platform's pinctrl and calling i2c_recover_bus()
when SDA is stuck low.

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
[wsa: inverted one logic for better readability, minor update to kdoc]
Signed-off-by: Wolfram Sang <wsa@kernel.org>