i2c: update stm32 i2c_lx to support LL clock control driver

After introducing STM32Cube based clock control driver for
stm32 family, update stm32 i2c_lx driver to support it.
Clean up will be done in a following commit.

Change-Id: Ie5059bf4122d65fab1a663a5b00e0d761850a49d
Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>
2 files changed