meson: Add meson build

The intent behind this commit is build obmc-phosphor-buttons with
meson, and then remove files related to cmake.

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: Iedf8c49224032e016fed3471e6e41f6055b09065
diff --git a/inc/power_button.hpp b/inc/power_button.hpp
index 9bf8744..73336ac 100644
--- a/inc/power_button.hpp
+++ b/inc/power_button.hpp
@@ -15,6 +15,8 @@
 */
 
 #pragma once
+#include "config.h"
+
 #include "button_factory.hpp"
 #include "button_interface.hpp"
 #include "common.hpp"