A test with the mock arch

Change-Id: I9af804df9cf1019f0b9c5535d7d79aca28229f88
diff --git a/src/cpu.c b/src/cpu.c
index 217baea..cec490e 100644
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -1,5 +1,7 @@
 #include "hf/cpu.h"
 
+#include <stdalign.h>
+
 #include "hf/arch/cpu.h"
 
 #include "hf/api.h"