This function is used to : -1- Enables GPIO clock and configures the I2C2 pins. -2- Enable the I2C2 peripheral clock. -3- Configure NVIC for I2C2. -4- Configure and Enable I2C2 functional parameters. -5- Disable I2C2 (to prevent misplaced start/stop condition during GPIO initialization phase on Slave side). Peripheral configuration is minimal configuration from reset values. Thus, some useless LL unitary functions calls below are provided as commented examples - setting is default configuration from reset.