fix: readme: typo Generic STM32F207ZG and STM32F217ZG#1788

fpistm merged 1 commit intostm32duino:mainstm32duino/Arduino_Core_STM32:mainfrom

ABOSTM:REAMDE_TYPO_F2x7ZGABOSTM/Arduino_Core_STM32:REAMDE_TYPO_F2x7ZGCopy head branch name to clipboard