clients: remove leftover from simple-dmabuf-drm

This header is not used anymore.

Signed-off-by: Simon Ser <contact@emersion.fr>
Fixes: 0a4f6e7d ("clients: drop simple-dmabuf-drm")
Reported-by: Marius Vlad <marius.vlad@collabora.com>
3 jobs for dmabuf-drm-remnant in 1 minute and 35 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Container Prep
passed #1045843
container_prep

00:00:28

 
  Build
passed #1045844
build-native-meson-default-options

00:01:06

passed #1045845
build-native-meson-no-gl-renderer

00:00:44