ARM: imx: clk-v610: Add clock for I2C2 and I2C3

Add support for clock gating of I2C2 and I2C3.
We use I2C2 in a (not yet mainlined) device tree.

Signed-off-by: Mirza Krak <mirza.krak@hostmobility.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>