Move the fpu settings across all cores so they are aligned.
Some cores did not have fpu set for ARMClang. I matched here both toolchains to set up
the fpu the same (Only exception is soft vs hard - that is separate issue I would not like to touch
in this series).
The new function (mbed_set_cpu_core_definitions()) should always be
called as it has defintions needed by Mbed OS to work with that
particular MCU core.
mbed_set_cpu_core_options() should only be called if a third-party
toolchain file has not been used as it has compile options that can
cause conflicts.