mtd: rawnand: arasan: Update NAND bus clock instead of system clock

In current implementation the Arasan NAND driver is updating the
system clock(i.e., anand->clk) in accordance to the timing modes
(i.e., SDR or NVDDR). But as per the Arasan NAND controller spec the
flash clock or the NAND bus clock(i.e., nfc->bus_clk), need to be
updated instead. This patch keeps the system clock unchanged and updates
the NAND bus clock as per the timing modes.

Fixes: 197b88f ("mtd: rawnand: arasan: Add new Arasan NAND controller")
CC: stable@vger.kernel.org # 5.8+
Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@xilinx.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220628154824.12222-2-amit.kumar-mahapatra@xilinx.com

Author: Amit Kumar Mahapatra

drivers/mtd/nand/raw/arasan-nand-controller.c

@@ -347,17 +347,17 @@ static int anfc_select_target(struct nand_chip *chip, int target)
 
 	/* Update clock frequency */
 	if (nfc->cur_clk != anand->clk) {
-		clk_disable_unprepare(nfc->controller_clk);
-		ret = clk_set_rate(nfc->controller_clk, anand->clk);
+		clk_disable_unprepare(nfc->bus_clk);
+		ret = clk_set_rate(nfc->bus_clk, anand->clk);
 		if (ret) {
 			dev_err(nfc->dev, "Failed to change clock rate\n");
 			return ret;
 		}
 
-		ret = clk_prepare_enable(nfc->controller_clk);
+		ret = clk_prepare_enable(nfc->bus_clk);
 		if (ret) {
 			dev_err(nfc->dev,
-				"Failed to re-enable the controller clock\n");
+				"Failed to re-enable the bus clock\n");
 			return ret;
 		}