soc: qcom: smp2p: Fix missing of_node_put() in smp2p_parse_ipc

The device_node pointer is returned by of_parse_phandle()  with refcount
incremented. We should use of_node_put() on it when done.

Fixes: 50e99641 ("soc: qcom: smp2p: Qualcomm Shared Memory Point to Point")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220308071942.22942-1-linmq006@gmail.com