boards/arm: Nucleo_F207zg: Enabling I2C support in device tree.

Enabling I2C support for Nucleo-F207zg in device tree.
This has been tested with mpu6050 sample application on I2C-1.
Documentation has been updated.

Signed-off-by: Krishna Mohan Dani <krishnamohan.d@hcl.com>
4 files changed