Split crypto_driver.h into one for each driver type

Split crypto_driver.h into 4:
* crypto_driver_common.h for common definitions, not meant to be
  included directly by driver code.
* crypto_accel_driver.h for drivers that work with transparent
  key material.
* crypto_se_driver.h for drivers that work with opaque key
  material.
* crypto_entropy_driver.h for drivers of entropy sources.

There is no code change in this commit, I only moved some code around.

include/psa/crypto_driver_common.h

@@ -0,0 +1,54 @@
+/**
+ * \file psa/crypto_driver_common.h
+ * \brief Definitions for all PSA crypto drivers
+ *
+ * This file contains common definitions shared by all PSA crypto drivers.
+ * Do not include it directly: instead, include the header file(s) for
+ * the type(s) of driver that you are implementing. For example, if
+ * you are writing a driver for a chip that provides both a hardware
+ * random generator and an accelerator for some cryptographic algorithms,
+ * include `psa/crypto_entropy_driver.h` and `psa/crypto_accel_driver.h`.
+ *
+ * This file is part of the PSA Crypto Driver Model, containing functions for
+ * driver developers to implement to enable hardware to be called in a
+ * standardized way by a PSA Cryptographic API implementation. The functions
+ * comprising the driver model, which driver authors implement, are not
+ * intended to be called by application developers.
+ */
+
+/*
+ *  Copyright (C) 2018, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+#ifndef PSA_CRYPTO_DRIVER_COMMON_H
+#define PSA_CRYPTO_DRIVER_COMMON_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+/* Include type definitions (psa_status_t, psa_algorithm_t,
+ * psa_key_type_t, etc.) and macros to build and analyze values
+ * of these types. */
+#include "crypto_types.h"
+#include "crypto_values.h"
+
+/** For encrypt-decrypt functions, whether the operation is an encryption
+ * or a decryption. */
+typedef enum {
+    PSA_CRYPTO_DRIVER_DECRYPT,
+    PSA_CRYPTO_DRIVER_ENCRYPT
+} psa_encrypt_or_decrypt_t;
+
+#endif /* PSA_CRYPTO_DRIVER_COMMON_H */