CVE-2022-50108 mfd: max77620: Fix refcount leak in max77620_initialise_fps

In the Linux kernel, the following vulnerability has been resolved: mfd: max77620: Fix refcount leak in max77620initialisefps ofgetchildbyname returns a node pointer with refcount incremented, we should use ofnodeput on it when not need anymore. Add missing ofnodeput to avoid refcount leak...