Simplest Zephyr module + bacnet_stack config and hello sample

ports/zephyr/main.c

@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2020 Legrand North America, Inc.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+/* Standard includes */
+#include <stdint.h>
+
+/* Zephyr includes */
+#include <init.h>
+#include <kernel.h>
+#include <sys/printk.h>
+#include <sys/util.h>
+#include <zephyr.h>
+
+#include <logging/log.h>
+LOG_MODULE_REGISTER(bacnet);
+
+/* To do:  init()
+
+static int init(struct device *unused)
+{
+    ARG_UNUSED(unused);
+
+    return 0;
+}
+
+SYS_INIT(init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);
+
+*/