Add clock config for the 25MHz crystal found on the discovery board.
Verified to work on the STM32F7-Disco.
Reviewed-by: Karl Palsson <karlp@tweak.net.au>
Modified namespaces and types->structs to avoid namespace pollution as
was fixed for other families in:
3a7cbec7: stm32l/stm32f: name space standardization [BREAKING]
Most changes are noise from doxygen.
Readme udpated to explain newer FP_FLAGS for m7
stm32f7 library is skipped if the toolchain doesn't support it yet.
