Add new package to debug multicast setups. This is required to use
kselftests script for network testing.
net-mtools is used instead of mtools as it does conflicts with another
package that is also called mtools.
Some additional patch from Vladimir Oltean are added to make the tool
works on kernel selftests scripts.
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
