igt/gem_mocs_settings: Force use of master device

To use SECURE batches requires root + master, and we need SECURE batches
to write to the privileged mocs registers, do be sure to use
drm_open_driver_master()

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104157
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
1 file changed