test: Rename unit-test flags

The UT_TESTF_ macros read as 'unit test test flags' which is not right.
Rename to UTF ('unit test flags').

This has the benefit of being shorter, which helps keep UNIT_TEST()
declarations on a single line.

Give the enum a name and reference it from the UNIT_TEST() macros while
we are here.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/dm/pinmux.c b/test/dm/pinmux.c
index cfbe3ef..92e5bc8 100644
--- a/test/dm/pinmux.c
+++ b/test/dm/pinmux.c
@@ -68,8 +68,7 @@
 
 	return 0;
 }
-
-DM_TEST(dm_test_pinmux, UT_TESTF_SCAN_FDT);
+DM_TEST(dm_test_pinmux, UTF_SCAN_FDT);
 
 static int dm_test_pinctrl_single(struct unit_test_state *uts)
 {
@@ -143,5 +142,4 @@
 	ut_asserteq(-EINVAL, ret);
 	return 0;
 }
-
-DM_TEST(dm_test_pinctrl_single, UT_TESTF_SCAN_FDT);
+DM_TEST(dm_test_pinctrl_single, UTF_SCAN_FDT);