SPM-MM: Re-enable disabled tests

The tests are actually passing now.

Change-Id: I0f9ef11dabded51daf791c42ce0e22ff222425db
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/spm/cactus_mm/cactus_mm_main.c b/spm/cactus_mm/cactus_mm_main.c
index 8452e65..bd64ccc 100644
--- a/spm/cactus_mm/cactus_mm_main.c
+++ b/spm/cactus_mm/cactus_mm_main.c
@@ -114,10 +114,7 @@
 	 */
 	misc_tests();
 	system_setup_tests();
-	/*
-	 * TODO: The following tests fail in the CI:
-	 * mem_attr_changes_tests(boot_info);
-	 */
+	mem_attr_changes_tests(boot_info);
 
 	/*
 	 * Handle secure service requests.