pinctrl: imx: use seq_puts() instead of seq_printf()

For a constant format without additional arguments, use seq_puts()
instead of seq_printf(). Also, it fixes the following checkpatch
warning.

WARNING: Prefer seq_puts to seq_printf
+		seq_printf(s, "N/A");

WARNING: Prefer seq_puts to seq_printf
+	seq_printf(s, "\n");

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/freescale/pinctrl-imx.c

@@ -371,7 +371,7 @@ static void imx_pinconf_dbg_show(struct pinctrl_dev *pctldev,
 	unsigned long config;
 
 	if (!pin_reg || pin_reg->conf_reg == -1) {
-		seq_printf(s, "N/A");
+		seq_puts(s, "N/A");
 		return;
 	}
 
@@ -390,7 +390,7 @@ static void imx_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
 	if (group > pctldev->num_groups)
 		return;
 
-	seq_printf(s, "\n");
+	seq_puts(s, "\n");
 	grp = pinctrl_generic_get_group(pctldev, group);
 	if (!grp)
 		return;