stm32: f4: flash: support extended sector ranges

F42xx and F43xx have extended sector ranges.

Reported-by: H2OBrain@irc
stm32: f24: flash: Make sure documentation matches the code

This clarifies the parameters, to ensure that the expected preshifted values
are used, as defined, rather than the field values, as the documentation
implied.  Code using the existing defines should see no difference.  Code using
the documentation and the logical bit field values will have been broken
anyway.