dm: Rename DM test flags to make them more generic

The test flags used by driver model are currently not available to other
tests. Rather than creating two sets of flags, make these flags generic
by changing the DM_ prefix to UT_ and moving them to the test.h header.

This will allow adding other test flags without confusion.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/dm/syscon.c b/test/dm/syscon.c
index b2d0ade..be23297 100644
--- a/test/dm/syscon.c
+++ b/test/dm/syscon.c
@@ -29,7 +29,7 @@
 
 	return 0;
 }
-DM_TEST(dm_test_syscon_base, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+DM_TEST(dm_test_syscon_base, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
 
 /* Test system controller finding */
 static int dm_test_syscon_by_driver_data(struct unit_test_state *uts)
@@ -46,7 +46,7 @@
 
 	return 0;
 }
-DM_TEST(dm_test_syscon_by_driver_data, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+DM_TEST(dm_test_syscon_by_driver_data, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);
 
 /* Test system controller by phandle */
 static int dm_test_syscon_by_phandle(struct unit_test_state *uts)
@@ -81,4 +81,4 @@
 
 	return 0;
 }
-DM_TEST(dm_test_syscon_by_phandle, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+DM_TEST(dm_test_syscon_by_phandle, UT_TESTF_SCAN_PDATA | UT_TESTF_SCAN_FDT);