samples/subsys/fs/zms: Allow it to run and add check

This sample could not run on any target as it depedend on zms
which is set by no board.
But it seems to run just fine in both allowed platforms,
so let's add a trivial twister check (so it actually passes instead
of waiting for ever), and remove that `depends on`.

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>