tests: Fix tests code and comments style

This patch applies clang-format settings to most of tests files. Some
files were fixed "by-hand" to exclude some lines, which whould be less
readable after automatic style fixing.
Moreover, some comments (mostly in tests/lib/edid-test.c) were adjusted
to match coreboot coding style guidelines.

Change-Id: I69f25a7b6d8265800c731754e2fbb2255f482134
Signed-off-by: Jakub Czapiga <jacz@semihalf.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60970
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>

tests/device/ddr4-test.c

@@ -33,9 +33,7 @@ static void ddr4_speed_mhz_to_mts_test(void **state)
 
 int main(void)
 {
-	const struct CMUnitTest tests[] = {
-		cmocka_unit_test(ddr4_speed_mhz_to_mts_test)
-	};
+	const struct CMUnitTest tests[] = {cmocka_unit_test(ddr4_speed_mhz_to_mts_test)};
 
 	return cb_run_group_tests(tests, NULL, NULL);
 }