Add fwu update agent deployment for linux-pc/posix

The fwu update agent can be deployed in different
execution environments to suite platform requirements.
This commit adds a deployment where the fwu update
agent runs within a command-line app for Posix
environments where the firmware image file is accessible
via standard file io. Can be built to run in a native PC
environment to enable a disk image file to be inspected.

Signed-off-by: Julian Hall <julian.hall@arm.com>
Change-Id: I3a652c7ab201c5b7059f8dd1bb6b590e6d8c4c37
diff --git a/deployments/fwu/env/posix/cmd_update_image.h b/deployments/fwu/env/posix/cmd_update_image.h
new file mode 100644
index 0000000..b0fe6ae
--- /dev/null
+++ b/deployments/fwu/env/posix/cmd_update_image.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2023, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#ifndef CMD_UPDATE_IMAGE_H
+#define CMD_UPDATE_IMAGE_H
+
+#include <string>
+#include <service/fwu/app/fwu_app.h>
+
+int cmd_update_image(
+	fwu_app &app,
+	const std::string &img_type_uuid,
+	const std::string &img_filename);
+
+#endif /* CMD_UPDATE_IMAGE_H */