Add support of NUCLEO_F746ZG and NUCLEO_F756ZG#1014

fpistm merged 1 commit intostm32duino:masterstm32duino/Arduino_Core_STM32:masterfrom

fpistm:Nucleo_F7x6ZGfpistm/Arduino_Core_STM32:Nucleo_F7x6ZGCopy head branch name to clipboard