tests: Always run all unit tests

tests: Always run all unit tests

So far, the semantics have been that run-unit-tests stopped at the first
test suite that failed. This hides useful signal in later tests, so
always run all tests and collect the result.

Change-Id: I407715f85513c2c95a1cf89cfb427317dff9fbab
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41773
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jan Dabros <jsd@semihalf.com>
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>