test: Drop the _test suffix on linker lists

test: Drop the _test suffix on linker lists

Most test suites have a _test suffix. This is not necessary as there is
also a ut_ prefix.

Drop the suffix so that (with future work) the suite name can be used as
the linker-list name.

Remove the suffix from the pytest regex as well, moving it to the top of
the file, as it is a constant.

Signed-off-by: Simon Glass <sjg@chromium.org>