torture: Add kvm.sh --debug-info argument

This commit adds a --debug-info argument to kvm.sh in order to ease
interpretation of addresses printed on the console and the like.
This argument also disables KASLR.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>