CVE-2022-50197 cpufreq: zynq: Fix refcount leak in zynq_get_revision

In the Linux kernel, the following vulnerability has been resolved: cpufreq: zynq: Fix refcount leak in zynqgetrevision offindcompatiblenode returns a node pointer with refcount incremented, we should use ofnodeput on it when done. Add missing ofnodeput to avoid refcount leak...