Add missing include

Fix build failures with config full

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/library/ssl_ciphersuites.c b/library/ssl_ciphersuites.c
index 3d4466a..793ec6a 100644
--- a/library/ssl_ciphersuites.c
+++ b/library/ssl_ciphersuites.c
@@ -28,6 +28,9 @@
 #include "mbedtls/ssl_ciphersuites.h"
 #include "mbedtls/ssl.h"
 #include "ssl_misc.h"
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#include "md_psa.h"
+#endif
 
 #include <string.h>