S2-LP: sync with development repository

[JarkkoPaso]

Description (required)

Nanostack RF driver updates for Mbed OS 5.15

Summary of change (What the change is for and why)

S2-LP RF driver:

• Updated to v1.0.1
• Fixed preamble configuration to follow Wi-SUN specification (depends on datarate)

Documentation (Details of any document updates required)

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Pull request type (required)

[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 (required)

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

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Reviewers (optional)

@mikter @juhhei01 @artokin

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[ciarmcom]

@JarkkoPaso, thank you for your changes.
@juhhei01 @artokin @mikter @ARMmbed/mbed-os-ipcore @ARMmbed/mbed-os-maintainers please review.

[0xc0170]

Please update the commit msg - "sync" does not say much to a reader.
Please state what version is this being updated to, plus points for adding what is this fixing

[0xc0170]

CI started

[mbed-ci]

Test run: SUCCESS

Summary: 11 of 11 test jobs passed
Build number : 1
Build artifacts