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).
Some armasm flags are passed to the ASM whilst we actually use armclang to invoke it. This causes build failures as armclang is not compatible with armasm flags.
This commit passes the same flags to all tools in the chain.
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.