arm64: dts: actions: s900-bubblegum-96: Enable I2C1 and I2C2

Add pinctrl definitions for Actions Semiconductor S900 I2C controllers.
Pinctrl definitions are only available for I2C0, I2C1, and I2C2.
Enable I2C1 and I2C2 exposed on the low speed expansion connector in
Bubblegum-96 board.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
[AF: Squashed]
Signed-off-by: Andreas Färber <afaerber@suse.de>