feature: add ohos build

Change-Id: Id8f4bdab7427d82c14a1bd15713146ba59c64102

meson_options.txt

@@ -6,7 +6,7 @@ option(
   type : 'array',
   value : ['auto'],
   choices : [
-    'auto', 'x11', 'wayland', 'haiku', 'android', 'windows',
+    'auto', 'x11', 'wayland', 'haiku', 'android', 'windows', 'ohos',
   ],
   description : 'window systems to support. If this is set to `auto`, all ' +
                 'platforms applicable will be enabled.'
@@ -18,7 +18,7 @@ option(
   value : 'auto',
   choices : [
     'auto', 'x11', 'wayland', 'haiku', 'android', 'windows',
-    'surfaceless', 'drm',
+    'surfaceless', 'drm', 'ohos',
   ],
   description : 'the window system EGL assumes for EGL_DEFAULT_DISPLAY',
 )