MAINTAINERS: Add Frederic and Neeraj to their RCU files

Adding Frederic as an RCU maintainer for kernel/rcu/tree_nocb.h given his
work with offloading and de-offloading callbacks from CPUs.  Also adding
Neeraj for kernel/rcu/tasks.h given his focused work on RCU Tasks Trace.
As in I am reasonably certain that each understands the full contents
of the corresponding file.

Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Frederic Weisbecker <frederic@kernel.org>

Author: paulmckrcu

MAINTAINERS

@@ -16298,6 +16298,8 @@ F:	tools/testing/selftests/resctrl/
 
 READ-COPY UPDATE (RCU)
 M:	"Paul E. McKenney" <paulmck@kernel.org>
+M:	Frederic Weisbecker <frederic@kernel.org> (kernel/rcu/tree_nocb.h)
+M:	Neeraj Upadhyay <quic_neeraju@quicinc.com> (kernel/rcu/tasks.h)
 M:	Josh Triplett <josh@joshtriplett.org>
 R:	Steven Rostedt <rostedt@goodmis.org>
 R:	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>