Add include for missing symbols

Fixes: wayland/weston#303
5 jobs for master in 3 minutes and 27 seconds (queued for 43 seconds)
latest
Status Job ID Name Coverage
  Container Prep
passed #936660
container_prep

00:00:25

 
  Build
passed #936661
build-native-meson-default-options

00:01:21

passed #936662
build-native-meson-no-gl-renderer

00:01:13

 
  Pages
passed #936663
pages

00:00:27

 
  Deploy
passed pages:deploy

00:00:25