compositor-rdp: refactor configuration API

Implement a "well" defined API to configure the rdp backend.
Following according to discution about libweston API.

Signed-off-by: Benoit Gschwind <gschwind@gnu-log.net>
Reviewed-by: David FORT <rdp.effort@gmail.com>
[Pekka: added missing headers to Makefile.am]
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/src/compositor-rdp.h b/src/compositor-rdp.h
new file mode 100644
index 0000000..dfa1759
--- /dev/null
+++ b/src/compositor-rdp.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright © 2016 Benoit Gschwind
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef WESTON_COMPOSITOR_RDP_H
+#define WESTON_COMPOSITOR_RDP_H
+
+#ifdef  __cplusplus
+extern "C" {
+#endif
+
+#include "compositor.h"
+
+#define WESTON_RDP_BACKEND_CONFIG_VERSION 1
+
+struct weston_rdp_backend_config {
+	struct weston_backend_config base;
+	int width;
+	int height;
+	char *bind_address;
+	int port;
+	char *rdp_key;
+	char *server_cert;
+	char *server_key;
+	int env_socket;
+	int no_clients_resize;
+};
+
+#ifdef  __cplusplus
+}
+#endif
+
+#endif /* WESTON_COMPOSITOR_RDP_H */