Add missing include

Fix build failures with config full

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/library/pk_wrap.c b/library/pk_wrap.c
index 087a7a3..a4c2a3b 100644
--- a/library/pk_wrap.c
+++ b/library/pk_wrap.c
@@ -25,6 +25,7 @@
 #include "pk_wrap.h"
 #include "pk_internal.h"
 #include "mbedtls/error.h"
+#include "md_psa.h"
 
 /* Even if RSA not activated, for the sake of RSA-alt */
 #include "mbedtls/rsa.h"