Cypress: Remove CY8CKIT_064S2_4343W files

Mbed OS 6 does not support this target.

targets/TARGET_Cypress/TARGET_PSOC6/TARGET_CY8CKIT_064S2_4343W/device/COMPONENT_CM4/device_cfg.h

@@ -1,27 +0,0 @@
-/*
- * Copyright (c) 2017-2018 Arm Limited
- * Copyright (c) 2020, Cypress Semiconductor Corporation. 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 __ARM_LTD_DEVICE_CFG_H__
-#define __ARM_LTD_DEVICE_CFG_H__
-
-#ifdef TFM_MULTI_CORE_MULTI_CLIENT_CALL
-#define NUM_MAILBOX_QUEUE_SLOT      4
-#endif
-
-#endif  /* __ARM_LTD_DEVICE_CFG_H__ */