Rename and retype hash test driver context structure

Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
diff --git a/include/psa/crypto_builtin_hash.h b/include/psa/crypto_builtin_hash.h
index 87e9711..b0332d6 100644
--- a/include/psa/crypto_builtin_hash.h
+++ b/include/psa/crypto_builtin_hash.h
@@ -92,11 +92,9 @@
  */
 #if defined(PSA_CRYPTO_DRIVER_TEST)
 
-typedef struct {
-    mbedtls_psa_hash_operation_t operation;
-} mbedtls_transparent_test_driver_hash_operation_t;
+typedef mbedtls_psa_hash_operation_t mbedtls_transparent_test_driver_hash_operation_t;
 
-#define MBEDTLS_TRANSPARENT_TEST_DRIVER_HASH_OPERATION_INIT { MBEDTLS_PSA_HASH_OPERATION_INIT }
+#define MBEDTLS_TRANSPARENT_TEST_DRIVER_HASH_OPERATION_INIT MBEDTLS_PSA_HASH_OPERATION_INIT
 
 #endif /* PSA_CRYPTO_DRIVER_TEST */