Turn the existing comments into doxygen comments to get more value
The f0 copy of this file originally had a copy/paste error in the documentation. F3 and L4 had the "right" name.
stm32f0, l3, l4 are currently sharing the same duplicated header, and stm32l0 uses the same peripheral. Stop copy-pasting stuff and centralize definitions into a iwdg_common_v2.h header.