I2C bus recovery need a pinmux and gpio. So i2c driver can switch
gpio mode to toggle scl to recovery bus.

Add pinctrl-single node to every i2c bus on fsl-ls2160 layerscape
platform.
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Reviewed-by: Frank Li <frank.li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>