tests/: Add helper.c unit tests

BUG=b:157280555
BRANCH=none
TEST=builds

Change-Id: If4a1fe7c499f51bb9d7cd48ef26caf9dfae3c1fa
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/41655
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
4 files changed