[rt] Enable NO_HZ_FULL
Adding this allows to use the cmdline arg "nohz_full" which can reduce rt
latencies. It will enable RCU_NOCB_CPU and allow use of "rcu_nocbs" as
well. For people not using these cmdline args it should just be a
noop.
Signed-off-by: Henning Schild <henning.schild@siemens.com>
Edited by Henning Schild