compositor-drm: Reject heads if HDR head exists

Don't attach a head to an output which has a head with HDR capabilities.

Signed-off-by: Harish Krupo <harish.krupo.kps@intel.com>
2 jobs for hdr in 39 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Container Prep
passed #368591
container_prep

00:00:18

 
  Build
failed #368592
build-native-meson

00:00:20

 
Name Stage Failure
failed
build-native-meson Build

clients/meson.build:363:2: ERROR: Dependency "libavutil" not found, tried pkgconfig

A full log can be found at /builds/harishkrupo/weston/build-weston-e9e66ef5113b9c4e16a7ab9fd58fb77ec3bd0b0c-368592/meson-logs/meson-log.txt
Uploading artifacts...
build-*/meson-logs: found 2 matching files
prefix-*: found 54 matching files

Uploading artifacts to coordinator... ok
id=368592 responseStatus=201 Created token=5P9B63J2
ERROR: Job failed: exit code 1