library/tests: replace md_psa.h with psa_util.h as include file for MD conversion

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/psa_crypto_ecp.c b/library/psa_crypto_ecp.c
index e4a372d..4164154 100644
--- a/library/psa_crypto_ecp.c
+++ b/library/psa_crypto_ecp.c
@@ -14,7 +14,7 @@
 #include "psa_crypto_core.h"
 #include "psa_crypto_ecp.h"
 #include "psa_crypto_random_impl.h"
-#include "md_psa.h"
+#include "mbedtls/psa_util.h"
 
 #include <stdlib.h>
 #include <string.h>