Provide a function in each CPU core module to set toolchain options.
All the functions have the same interface therefore the CMake source
file including the module always calls the same function regardless
of which cpu core module is actually included.
When the `mbed-os` target is broken up into multiple libraries, a
library other than `mbed-os` might need to set the toolchain options.
This will be possible by simply including the module and calling the
function with the target and toolchain for which to set the options.
The version number was required previously when ARM Compiler 5
and ARM Compiler 6 were both supported. There was a significant
underlying change between the two that justified having distinct
build options settinfgs. It is very unlikely that such a major change will happen
between ARM Compiler 6 and future versions. It is therefore also very unlikely
that distinct option settings for future versions will be needed.
We should therefore avoid appending version number the same way we do not
append it to GCC toolchain configuration settings.
Hugues Kamba
Devaraj Ranganna