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/eth.c b/test/dm/eth.c
index b58c964..1a3eb18 100644
--- a/test/dm/eth.c
+++ b/test/dm/eth.c
@@ -13,10 +13,11 @@
 #include <log.h>
 #include <malloc.h>
 #include <net.h>
+#include <asm/eth.h>
 #include <dm/test.h>
 #include <dm/device-internal.h>
 #include <dm/uclass-internal.h>
-#include <asm/eth.h>
+#include <test/test.h>
 #include <test/ut.h>
 
 #define DM_TEST_ETH_NUM		4