Merge topic 'ghs_initial_setup'

aa59eaac4f GHS: Allow setting GHS variables from toolchain file
ab6f0b51b1 GHS: Add note about -T and path style
a55b5c4e18 GHS: Update BSP selection logic
0427f22539 GHS: Update RTOS selection logic
e006b87cc6 GHS: GHSMULTI - Update documentation to match implementation
83eb5695e9 GHS: Update toolset selection logic
8114ddcad1 GHS: Continue splitting variables used by generator
831607889f GHS: Update selection of primaryTarget in MULTI project file
...

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: buildbot <buildbot@kitware.com>
Merge-request: !6715