dm: core: Drop header files from dm/test.h

These header file should not be included in other header files. Remove
them and add to each individual file. Add test/test.h to test/ui.h since
that is a reasonable place.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/dm/axi.c b/test/dm/axi.c
index e1155a5..5b1bbab 100644
--- a/test/dm/axi.c
+++ b/test/dm/axi.c
@@ -8,9 +8,10 @@
 #include <axi.h>
 #include <dm.h>
 #include <log.h>
-#include <dm/test.h>
-#include <test/ut.h>
 #include <asm/axi.h>
+#include <dm/test.h>
+#include <test/test.h>
+#include <test/ut.h>
 
 /* Test that sandbox AXI works correctly */
 static int dm_test_axi_base(struct unit_test_state *uts)