Add selftests

Add selftests for key wrapping
diff --git a/programs/test/selftest.c b/programs/test/selftest.c
index df5634d..f923a43 100644
--- a/programs/test/selftest.c
+++ b/programs/test/selftest.c
@@ -57,6 +57,7 @@
 #include "mbedtls/ecp.h"
 #include "mbedtls/ecjpake.h"
 #include "mbedtls/timing.h"
+#include "mbedtls/nist_kw.h"
 
 #include <string.h>
 
@@ -208,6 +209,9 @@
 #if defined(MBEDTLS_CCM_C) && defined(MBEDTLS_AES_C)
     {"ccm", mbedtls_ccm_self_test},
 #endif
+#if defined(MBEDTLS_NIST_KW_C) && defined(MBEDTLS_AES_C)
+    {"nist_kw", mbedtls_nist_kw_self_test},
+#endif
 #if defined(MBEDTLS_CMAC_C)
     {"cmac", mbedtls_cmac_self_test},
 #endif