hmi-controller: allocate application layers for multi-screen
hmi-controller: allocate application layers for multi-screen

To locate surfaces of application on multi screens, multi layers are
created baseod on application-layer-id + base-layer-id-offset x N.

Signed-off-by: Nobuhiko Tanibata <92313f26b3566e64b50391ce0051fc0e1f775402@xddp.denso.co.jp>
Reviewed-by: Pekka Paalanen <0f6ae7001e34c37b02fb2c1c2573ddf8f442136a@collabora.co.uk>

Fantu/compositor-spice,sir-murray/weston,giucam/weston,Fantu/compositor-spice,krezovic/weston,Gnurou/weston,giucam/weston,sir-murray/weston,Fantu/compositor-spice,Gnurou/weston,krezovic/weston