arm64: defconfig: Select CONFIG_PINCTRL_IMX8MN by default

Enable CONFIG_PINCTRL_IMX8MN by default to support i.MX8MN
pinctrl driver.
Signed-off-by: NAnson Huang <Anson.Huang@nxp.com>
Reviewed-by: NDong Aisheng <aisheng.dong@nxp.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm64/configs/defconfig

@@ -394,6 +394,7 @@ CONFIG_SPMI=y
 CONFIG_PINCTRL_SINGLE=y
 CONFIG_PINCTRL_MAX77620=y
 CONFIG_PINCTRL_IMX8MM=y
+CONFIG_PINCTRL_IMX8MN=y
 CONFIG_PINCTRL_IMX8MQ=y
 CONFIG_PINCTRL_IMX8QXP=y
 CONFIG_PINCTRL_IPQ8074=y