tools: acrn-crashlog: framework of acrn-crashlog

This is the first patch of acrn-crashlog.

This patch initializes the framework of acrn-crashlog: acrnprobe,
common, data, and usercrash. And it initializes the Makefile for
each part.

Signed-off-by: Liu Xinwu <xinwu.liu@intel.com>
Signed-off-by: CHEN Gang <gang.c.chen@intel.com>
Reviewed-by: Zhang Yanmin <yanmin.zhang@intel.com>
Reviewed-by: Liu Chuansheng <chuansheng.liu@intel.com>
Reviewed-by: Zhao Yakui <yakui.zhao@intel.com>
Reviewed-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>
Acked-by: Eddie Dong <Eddie.dong@intel.com>

tools/acrn-crashlog/usercrash/client.c

@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) <2018> Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/**
+ * Usercrash works as C/S model: usercrash_c works as usercrash client to
+ * collect crash logs and information once crash event occurs. For each time,
+ * usercrash_c receives 3 params from core_dump and sends connect request event
+ * to usercrash_s, then it receives file fd from server to fill crash info into
+ * the file. After this work is done, it will notify server that dump work is
+ * completed.
+ */
+
+int main(void)
+{
+	//TO BE DONE
+	//This empty function is to satisfy the dependency of Makefile.
+	//This is the entry of usercrash_c, the implementation will be
+	//filled by following patches.
+	return 0;
+}