remoteproc: qcom_wcnss: Add missing of_node_put() in wcnss_alloc_memory_region

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

Fixes: aed361ad ("remoteproc: qcom: Introduce WCNSS peripheral image loader")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220308063102.10049-1-linmq006@gmail.com