* [gcc][armcc][armclang] rtconfig.CROSS_TOOL->rtconfig.PLATFORM
2. Bsp stm32l452-st-nucleo has been tested with NUCLEO-L452RE board. 3. Modify the applications SConscript of bsp stm32f103-yf-ufun, using new method. 4. Modify README of bsp stm32f072-st-nucleo.