[DISCO_F429ZI] clock frequency

Original STM32Cube F4 driver sets SYSCLK for STM32F429 to 16MHz. This adds a 168MHz and 180MHz configuration to system_stm32f4xx.c generated by STM32CubeMX code generator. The rtos clock configuration is changed too. In singletest.py run everything is OK.

Perhaps @bcostm wants to inform the STM32Cube people about the wrong configuration of their fastest mcu running only with 16MHz not only in the driver template but also in the examples.