VRBRAIN specific pull request

This pull request only affects VRBRAIN boards. It would be nice to have it merged only to be able to eliminate this branch.
The commit https://github.com/virtualrobotix/ardupilot/commit/bec3a4faeef5e3b356c482d46fdd7cb5f1a2199f
has already been merged into master. It can be merged or not.
Up to you.

Thanks.