turnip: remove pre-emption marker

turnip doesn't implement pre-emption, this hasn't been a problem with drm
backend since the kernel driver doesn't implement it either, however this
causes issues with kgsl backend.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Part-of: <!6994>
2 jobs for master in 1 minute and 10 seconds (queued for 6 seconds)
Status Job ID Name Coverage
  Container+Docs
passed #4826277
git_archive

00:00:17

 
  Git Archive
passed #4826279
packet.net
make git archive

00:00:53