irqchip/gic/realview: Fix refcount leak in realview_gic_of_init

irqchip/gic/realview: Fix refcount leak in realview_gic_of_init

of_find_matching_node_and_match() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
Add missing of_node_put() to avoid refcount leak.

Fixes: f17c75ab0609 ("irqchip/gic/realview: Support more RealView DCC variants")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220601080930.31005-2-linmq006@gmail.com