memory: samsung: exynos5422-dmc: Fix refcount leak in of_get_dram_timings

In the Linux kernel, the following vulnerability has been resolved: memory: samsung: exynos5422-dmc: Fix refcount leak in of_get_dram_timings of_parse_phandle() returns a node pointer with refcount incremented, we should use of_node_put() on it when not need anymore. This function doesn't call of_node_put() in some error paths. To unify the structure, Add put_node label and goto it on errors.