Set DOMAIN_NS=1 only for _NS cores. We had it otherway around.
I verified one non NS target that was failing to build, plus also checked the old tools
that had this definitions:
```
91: "Cortex-M23-NS": ["__CORTEX_M23", "ARM_MATH_ARMV8MBL", "DOMAIN_NS=1",
92 "__CMSIS_RTOS", "__MBED_CMSIS_RTOS_CM"],
93 "Cortex-M23": ["__CORTEX_M23", "ARM_MATH_ARMV8MBL", "__CMSIS_RTOS",
94 "__MBED_CMSIS_RTOS_CM"],
```
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.
Meano
Martin Kojtal
Hugues Kamba
Jamie Smith
Rajkumar Kanagaraj