* also added a trailing underscore to header guards for consistency
Commit for PR 2623, repairing header file include guards.
This PR is intended to fix the include guards in files under RIOT/boards
SQUASH ME: fix underscore removal overdos
SQUASH ME: consistent macro naming
SQUASH ME: missed that one
SQUASH ME: fixed overdo
SQUASH ME: consistency
This change allows drivers (or any module for that matter) to provide
features. This is e.g. useful if a board does not have a transceiver,
but your application uses `USEMODULE += some_driver`, which implements
the transceiver interface.
The line `FEATURES_PROVIDED += some_feature` should go to the guarded
block in `{sys,drivers}/Makefile.include`.
