The call to of_get_child_by_name returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.
Detected by coccinelle with the following warnings:
./drivers/pinctrl/pinctrl-pistachio.c:1422:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1360, but without a corresponding object release within this function.