clk: samsung: Fix memory leak in _samsung_clk_register_pll()

In the Linux kernel, the following vulnerability has been resolved:

clk: samsung: Fix memory leak in _samsung_clk_register_pll()

If clk_register() fails, @pll->rate_table may have allocated memory by

kmemdup(), so it needs to be freed, otherwise will cause memory leak

issue, this patch fixes it.