[U-Boot] [PATCH 1/2 v2] i2c: soft_i2c: add simple GPIO implementation

[Thomas Chou]

Mike Frysinger wrote:
> Since the vast majority of GPIO I2C implementations behave the same way,
> support the common GPIO framework with default settings.
> 
> This adds two new defines CONFIG_SOFT_I2C_GPIO_{SCL,SDA} so that boards
> which want GPIO I2C support need only define these.
> 
> Signed-off-by: Mike Frysinger <vapier at gentoo.org>
> Tested-by: Thomas Chou <thomas at wytron.com.tw>
> ---
> v2
> 	- stub out tristate/active by default and let the gpios handle things
> 	  in the sda/scl macros
> 

Tested v2 on nios2 boards.

Tested-by: Thomas Chou <thomas at wytron.com.tw>