applications: Add MQTT File Downloader config for keyword detection

THe MQTT File Streams library allows a MQTTFileDownloader_config.h file
to be provided, which defines custom values for build configuration
macros. This commit adds a MQTTFileDownloader_config.h file for the
keyword detection example. This file defines the block size that should
be used when downloading the firmware image.

Signed-off-by: Chuyue Luo <[email protected]>

Author: chuyue-luo-arm

applications/keyword_detection/configs/aws_configs/MQTTFileDownloader_config.h

@@ -0,0 +1,31 @@
+/*
+ * Copyright Amazon.com, Inc. and its affiliates. All Rights Reserved.
+ * Copyright 2024 Arm Limited and/or its affiliates
+ * <[email protected]>
+ *
+ * SPDX-License-Identifier: MIT
+ * Licensed under the MIT License. See the LICENSE accompanying this file
+ * for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+/**
+ * @file MQTTFileDownloader_config.h
+ * @brief MQTT File Streams options.
+ */
+
+#ifndef MQTT_FILE_DOWNLOADER_CONFIG_H
+#define MQTT_FILE_DOWNLOADER_CONFIG_H
+
+/* Standard includes */
+#include <stdint.h>
+
+/**
+ * @ingroup mqtt_file_downloader_const_types
+ * @brief Configure the Maximum size of the data payload. The
+ * smallest value is 256 bytes, maximum is 128KB. For more see
+ * https://docs.aws.amazon.com/general/latest/gr/iot-core.html
+ */
+#define mqttFileDownloader_CONFIG_BLOCK_SIZE    4096U
+
+#endif /* MQTT_FILE_DOWNLOADER_CONFIG_H */