Bluetooth: Mesh: Update spec ref 1.0.1->1.1

Updates Bluetooth mesh specification references:

- Change "Profile" to "Protocol" since the main specification has
changed its name.
- Update/align formating of specification references. This will
make it easier to find spec references in the future.
- Change some section references to point to the correct section of the
newest version of the specification (v1.1).

Signed-off-by: Anders Storrø <anders.storro@nordicsemi.no>