clk: imx: Free pll on error path

For an unknown pll type the error path neglects to free the memory just
allocated. Add the free.

This issue was found by Smatch.

Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>

drivers/clk/imx/clk-pll14xx.c

@@ -409,6 +409,7 @@ struct clk *imx_clk_pll14xx(const char *name, const char *parent_name,
 	default:
 		pr_err("%s: Unknown pll type for pll clk %s\n",
 		       __func__, name);
+		kfree(pll);
 		return ERR_PTR(-EINVAL);
 	};