Rename and retype hash test driver context structure

Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
diff --git a/include/psa/crypto_driver_contexts.h b/include/psa/crypto_driver_contexts.h
index 524329d..fdf178f 100644
--- a/include/psa/crypto_driver_contexts.h
+++ b/include/psa/crypto_driver_contexts.h
@@ -43,7 +43,7 @@
     unsigned dummy; /* Make sure this structure is always non-empty */
     mbedtls_psa_hash_operation_t mbedtls_ctx;
 #if defined(PSA_CRYPTO_DRIVER_TEST)
-    mbedtls_transparent_test_driver_hash_operation_t test_ctx;
+    mbedtls_transparent_test_driver_hash_operation_t test_driver_ctx;
 #endif
 } psa_driver_hash_context_t;