drm/tests: helpers: Add module infos

The MODULE_LICENSE macro is missing from the kunit helpers file, thus
leading to a build error.

Let's introduce it along with MODULE_AUTHOR.

Fixes: 44a3928324e9 ("drm/tests: Add Kunit Helpers")
Reported-by: Stephen Rothwell <[e-mail]>
Reviewed-by: Maíra Canal <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Maxime Ripard <[e-mail]>

drivers/gpu/drm/tests/drm_kunit_helpers.c

···
 
 	return drm;
 }
+
+MODULE_AUTHOR("Maxime Ripard <[e-mail]>");
+MODULE_LICENSE("GPL");