Merge header file changes

* 'master' of https://github.com/NordicSemiconductor/pc-ble-driver: (52 commits)
  Re-add sdk folder to ignore file
  Remove commented out lines
  Add missing handling of keyset
  Updated fix, build test is required
  Fixed building issue on Linux
  Simplify baud rate logic by specifying init values
  Fixed whitespacing issue in the code copied from sdk
  Fixed merge conflict in app_ble_gap_sec_keys.cpp in v5
  Fixed merge conflict in ble_gap_evt_app.c in v5
  Fixed merge conflict in app_ble_gap_sec_keys.h in v5
  Fixed merge conflict in ble_gap_impl.cpp
  Update connectivity hex files
  Update connectivity hex files
  Add optional command line argument for specifying baud rate
  Reduce max packet size
  Re-add changes that were mistakenly removed
  Add script for donwloading sdk
  Bump version number in connectivity patch files
  Add updated v2 connectivity hex files
  Remove references to v3
  ...

Feature/s132v5

Using implementation from SDK unchanged instead

Add optional command line argument for specifying baud rate

Print feedback of supported baud rates if an unsupported value has been provided.

To avoid having to recompile the examples when switching between different baud rates, it can with this change be specified from the command line when running the examples.

When using max packet size of 700, the 115k2 variant of connectivity would fail with timeout when attempting to connect. Reducing to does seems to fix the problem. The root cause of the issue is not clear at the moment.

Update connectivity to add fix for att mtu

* Update connectivity bootstrap and patch files
* Increase buffers to avoid overrun when using large mtu sizes.
* Use SDK v12.2 instead of v12.1 to include fixes.
* Bump connectivity version number to 1.2.0.
* Leave default baud rate at 1Mbps.
* Add updated connectivity hex files.
* Remove old connectivity hex files.
* Add --reduce-paths option to keil proj files to to workaround Keil path issue.