mtd: rawnand: mpc5121: Use helper function devm_clk_get_enabled()

Since commit 7ef9651e9792 ("clk: Provide new devm_clk helpers for prepared
and enabled clocks"), devm_clk_get() and clk_prepare_enable() can now be
replaced by devm_clk_get_enabled() when driver enables (and possibly
prepares) the clocks for the whole lifetime of the device. Moreover, it is
no longer necessary to unprepare and disable the clocks explicitly.

Reviewed-by: Miquel Raynal <[e-mail]>
Signed-off-by: Li Zetao <[e-mail]>
Signed-off-by: Miquel Raynal <[e-mail]>
Link: https://lore.kernel.org/linux-mtd/[e-mail]

drivers/mtd/nand/raw/mpc5121_nfc.c

···
 	struct nand_chip *chip = mtd_to_nand(mtd);
 	struct mpc5121_nfc_prv *prv = nand_get_controller_data(chip);
 
-	clk_disable_unprepare(prv->clk);
-
 	if (prv->csreg)
 		iounmap(prv->csreg);
 }
···
 	}
 
 	/* Enable NFC clock */
-	clk = devm_clk_get(dev, "ipg");
+	clk = devm_clk_get_enabled(dev, "ipg");
 	if (IS_ERR(clk)) {
-		dev_err(dev, "Unable to acquire NFC clock!\n");
+		dev_err(dev, "Unable to acquire and enable NFC clock!\n");
 		retval = PTR_ERR(clk);
-		goto error;
-	}
-	retval = clk_prepare_enable(clk);
-	if (retval) {
-		dev_err(dev, "Unable to enable NFC clock!\n");
 		goto error;
 	}
 	prv->clk = clk;