ecore-evas-drm: Check for XDG_SEAT existence
Small patch to allow specifying a different seat via XDG_SEAT env
variable. If no seat name is passed as ecore_evas options, then we
would always default to 'seat0'. As this may not be desirable in all
situations, allow for an override via XDG_SEAT env var.
Signed-off-by: Chris Michael <email@example.com>