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/meson_options.txt b/meson_options.txt
new file mode 100644
index 0000000..fa7aa00
--- /dev/null
+++ b/meson_options.txt
@@ -0,0 +1,6 @@
+option(
+    'id-led-group',
+    type : 'string',
+    value: 'enclosure_identify',
+    description : 'The identify LED group name'
+)