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/spmi.c b/test/dm/spmi.c
index 668b7e1..4aae1f1 100644
--- a/test/dm/spmi.c
+++ b/test/dm/spmi.c
@@ -14,6 +14,7 @@
 #include <power/pmic.h>
 #include <spmi/spmi.h>
 #include <asm/gpio.h>
+#include <test/test.h>
 #include <test/ut.h>
 
 /* Test if bus childs got probed propperly*/