At present these are large enough to hold 20 bytes of symbol data. Add
four more bytes so we can add another test.

Unfortunately at present this involves changing a few test files to make
room. We could adjust the test files to not specify sizes for entries.
Then we could make the tests check the actual sizes. But for now, leave it
as it is, since the effort is minor.
Signed-off-by: NSimon Glass <sjg@chromium.org>