sqm-scripts: use masks with markings

Apply mask for markings to enable co-existence with multiwan, mwan3 etc.

Matches source tree at https://github.com/dtaht/ceropackages-3.10/tree/d82ef2a81cb71fc4749ab4a353e6d9307c37dc4b

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>