rcu: Update stray documentation references to rcu_dynticks_eqs_{enter, exit}()

rcu: Update stray documentation references to rcu_dynticks_eqs_{enter, exit}()

rcu_dynticks_eqs_{enter, exit}() have been replaced by their
context-tracking counterparts since commit:

  171476775d32 ("context_tracking: Convert state to atomic_t")

Update the stray documentation references.

Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>