Remove MBEDTLS_GCM_ALT

Signed-off-by: Thomas Daubney <[email protected]>

tests/include/alt-dummy/gcm_alt.h

@@ -1,16 +0,0 @@
-/* gcm_alt.h with dummy types for MBEDTLS_GCM_ALT */
-/*
- *  Copyright The Mbed TLS Contributors
- *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
- */
-
-#ifndef GCM_ALT_H
-#define GCM_ALT_H
-
-typedef struct mbedtls_gcm_context {
-    int dummy;
-}
-mbedtls_gcm_context;
-
-
-#endif /* gcm_alt.h */