Add the Doxygen note to non-supported RTOS kernel APIs.

[rajkan01]

Summary of changes

Added the Doxygen note for non-supported RTOS kernel APIs in bare metal profile.

Impact of changes

With these changes, "Bare metal profile: This API is not supported" Doxygen note will be visible in the RTOS kernel APIs documentation for those non-supported in bare metal.

Migration actions required

None.

Documentation

None.

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Pull request type

[x] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[] Feature update (New feature / Functionality change / New API)
[] Major update (Breaking change E.g. Return code change / API behaviour change)

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Test results

[x] No Tests required for this change (E.g docs only update)
[] Covered by existing mbed-os tests (Greentea or Unittest)
[] Tests / results supplied as part of this PR

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Reviewers

@evedon

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[0xc0170]

CI started

[mbed-ci]

Test run: SUCCESS

Summary: 6 of 6 test jobs passed
Build number : 1
Build artifacts