ARM: dts: pbab01: move i2c pins and frequency configuration into pfla02

Since pins and frequency are specific to module (pfla02), not base board
(pbab02), it is better to be initialized in corresponding dts file.

This patch fixes i2c2, i2c3 pin configuration which caused messages:

imx6q-pinctrl 20e0000.iomuxc: no groups defined in /soc/aips-bus@02000000/iomuxc@020e0000/i2c2grp
imx6q-pinctrl 20e0000.iomuxc: no groups defined in /soc/aips-bus@02000000/iomuxc@020e0000/i2c3grp
imx6q-pinctrl 20e0000.iomuxc: unable to find group for node i2c2grp
imx6q-pinctrl 20e0000.iomuxc: unable to find group for node i2c3grp

Signed-off-by: Dmitry Lavnikevich <d.lavnikevich@sam-solutions.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>