test: add firmware_class loader test

This provides a simple interface to trigger the firmware_class loader
to test built-in, filesystem, and user helper modes. Additionally adds
tests via the new interface to the selftests tree.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --cc lib/Kconfig.debug
Simple merge

diff --cc lib/Makefile
Simple merge

diff --cc lib/test_firmware.c
Simple merge

diff --cc tools/testing/selftests/Makefile
Simple merge

diff --cc tools/testing/selftests/firmware/Makefile
Simple merge

diff --cc tools/testing/selftests/firmware/fw_filesystem.sh
Simple merge

diff --cc tools/testing/selftests/firmware/fw_userhelper.sh
Simple merge