Remove MBEDTLS_GCM_ALT

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/tests/include/alt-dummy/gcm_alt.h b/tests/include/alt-dummy/gcm_alt.h
deleted file mode 100644
index cfa73d2..0000000
--- a/tests/include/alt-dummy/gcm_alt.h
+++ /dev/null
@@ -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 */
diff --git a/tests/include/test/psa_crypto_helpers.h b/tests/include/test/psa_crypto_helpers.h
index 5bab8e4..062beaf 100644
--- a/tests/include/test/psa_crypto_helpers.h
+++ b/tests/include/test/psa_crypto_helpers.h
@@ -293,8 +293,7 @@
  *  \param  alg             The AEAD algorithm.
  *  \param  nonce_length    The nonce length in number of bytes.
  */
-#if defined(MBEDTLS_GCM_ALT) || \
-    defined(MBEDTLS_PSA_ACCEL_ALG_GCM)
+#if defined(MBEDTLS_PSA_ACCEL_ALG_GCM)
 #define MBEDTLS_TEST_HAVE_ALT_GCM  1
 #else
 #define MBEDTLS_TEST_HAVE_ALT_GCM  0