This _breaks_ your gpio code for F2 and F4. It makes them consistent
with the reference manual, and more consistent with all other families
and general expectations.
OLD code -> NEW code
RCC_AHB1RSTR_IOPxRST -> RCC_AHB1RSTR_GPIOxRST
RCC_AHB1ENR_IOPIxEN -> RCC_AHB1ENR_GPIOxEN
RCC_AHB1LPENR_IOPxLPEN -> RCC_AHB1LPENR_GPIOxLPEN
[We're not actually breaking it, see the next commit for deprecated
aliases]
Yonghua Zheng
eeef996cb0