torture: Make --kcsan specify lockdep

The --kcsan argument to kvm.sh adds CONFIG_KCSAN_VERBOSE=y in order to
get more detail from the KCSAN reports.  However, this Kconfig option
requires lockdep to be enabled.  This commit therefore causes --kcsan
to also enable lockdep.

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