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/src/gpio.cpp b/src/gpio.cpp
index 52ffed6..faf5639 100644
--- a/src/gpio.cpp
+++ b/src/gpio.cpp
@@ -14,9 +14,9 @@
 // limitations under the License.
 */
 
-#include "gpio.hpp"
+#include "config.h"
 
-#include "settings.hpp"
+#include "gpio.hpp"
 
 #include <fcntl.h>
 #include <unistd.h>