docs/manual: update graph-depends documentation about --stop-on

This commit updates the graph-depends documentation to take into
account the new 'host' keyword that can be passed to the --stop-on and
--exclude options.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>