Configuration Options for different hardware and compiler toolchains

[ReinhardKeil]

https://github.com/Arm-Examples/CMSIS-Executorch/blob/main/model/aot_model.py#L26 uses different configuration options for Ethos hardware:

• These options should be documented.
• Options should be configurable in a consistent way and potentially exported from the IDE project

https://github.com/Arm-Examples/CMSIS-Executorch/blob/main/.docker/Dockerfile uses GCC.

• Compiler toolchain should be configurable to ATfE (CLANG) and potentially exported from the IDE project