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>
diff --git a/include/dm/test.h b/include/dm/test.h
index 3cbf2c7..4aabb46 100644
--- a/include/dm/test.h
+++ b/include/dm/test.h
@@ -143,7 +143,7 @@
 
 /* Declare a new driver model test */
 #define DM_TEST(_name, _flags) \
-	UNIT_TEST(_name, UTF_DM | UTF_CONSOLE | (_flags), dm_test)
+	UNIT_TEST(_name, UTF_DM | UTF_CONSOLE | (_flags), dm)
 
 /*
  * struct sandbox_sdl_plat - Platform data for the SDL video driver