Make compiler happy when MBEDTLS_USE_UECC disabled
diff --git a/tinycrypt/ecc_dsa.c b/tinycrypt/ecc_dsa.c
index d3e72a5..ff8a78a 100644
--- a/tinycrypt/ecc_dsa.c
+++ b/tinycrypt/ecc_dsa.c
@@ -292,5 +292,6 @@
 	/* Accept only if v == r. */
 	return (int)(uECC_vli_equal(rx, r, num_words) == 0);
 }
-
+#else
+typedef int mbedtls_dummy_uecc_def;
 #endif /* MBEDTLS_USE_UECC */