tests: More thorough tests of libfdt overlay application without dtc

At the moment we have some rudimentary tests of the fdt_overlay_apply()
function which don't rely on overlay generation support in dtc.  This is
done by avoiding any external references in the sample overlay, in
particularly using the 'target-path' syntax instead of 'target' to avoid
needing external references in the fragment targets.  Thus this test case
doesn't exercise libfdt's processing of the __fixups__ node at all.

We do test that somewhat in combination with dtc's overlay support.
However, in the interests of being able to quickly determine which side a
bug is on, it would be nice to exercise this without requiring the dtc
support.

This adds testcases to do so, by making some examples with manually
constructed __symbols__ and __fixups__ nodes.  In addition we rename some
of the test data files and add some extra check_path tests to make it a bit
clearer what's going on here.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
4 files changed