addrmap: Support on sandbox

Update this feature so that it works on sandbox, using a basic identity
mapping. This allows us to run the 'ut addrmap' test.

Also fix up the test to use the correct macros to access the linker
list, so that the 'ut addrmap' command actually works.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/cmd/addrmap.c b/test/cmd/addrmap.c
index fb74448..1eb5955 100644
--- a/test/cmd/addrmap.c
+++ b/test/cmd/addrmap.c
@@ -29,9 +29,8 @@
 
 int do_ut_addrmap(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 {
-	struct unit_test *tests = ll_entry_start(struct unit_test,
-						 addrmap_test);
-	const int n_ents = ll_entry_count(struct unit_test, addrmap_test);
+	struct unit_test *tests = UNIT_TEST_SUITE_START(addrmap_test);
+	const int n_ents = UNIT_TEST_SUITE_COUNT(addrmap_test);
 
 	return cmd_ut_category("cmd_addrmap", "cmd_addrmap_", tests, n_ents,
 			       argc, argv);