remoteproc: k3-r5: Fix refcount leak in k3_r5_cluster_of_init

In the Linux kernel, the following vulnerability has been resolved: remoteproc: k3-r5: Fix refcount leak in k3_r5_cluster_of_init Every iteration of for_each_available_child_of_node() decrements the reference count of the previous node. When breaking early from a for_each_available_child_of_node() loop, we need to explicitly call of_node_put() on the child node. Add missing of_node_put() to avoid refcount leak.