util/lint/kconfig_lint: change warning levels and text

- Add an exception for MAINBOARD_POWER_ON_AFTER_POWER_FAIL when checking
- With those exceptions set, we don't have anymore #define or #ifdef
warnings, so turn them to errors so no more can be pushed.
- Change the definition of an unused symbol from a warning to a note.
There are times when unused symbols are expected.
- Upgrade the warning for loading Kconfig files multiple times from
a warning to an error.

Change-Id: I6dcb06d4f0b099d5ccaf7643e72dd790719bdf58
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/16840
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

0 files changed, 0 insertions, 0 deletions