test: Move the FIT test into the correct place

Move this test so that it will run when 'make tests' is used.

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

diff --git a/test/image/test-fit.py b/test/py/tests/test_fit.py
similarity index 100%
rename from test/image/test-fit.py
rename to test/py/tests/test_fit.py