mtd: mxc_nand: add missing clk_disable_unprepare() in mxcnd_remove()

clock source is prepared and enabled by clk_prepare_enable() in
mxcnd_probe() function, but no disable/unprepare in mxcnd_remove().
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>

drivers/mtd/nand/mxc_nand.c

@@ -1577,6 +1577,8 @@ static int mxcnd_remove(struct platform_device *pdev)
 	struct mxc_nand_host *host = platform_get_drvdata(pdev);
 
 	nand_release(&host->mtd);
+	if (host->clk_act)
+		clk_disable_unprepare(host->clk);
 
 	return 0;
 }