pinctrl: imx: Support building SCU pinctrl core driver as module

Change PINCTR_IMX_SCU to tristate, add module author, description
and license to support building SCU pinctrl core driver as module.

Signed-off-by: Anson Huang <[e-mail]>
Reviewed-by: Dong Aisheng <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/freescale/Kconfig

···
 	select REGMAP
 
 config PINCTRL_IMX_SCU
-	bool
+	tristate
 	depends on IMX_SCU
 	select PINCTRL_IMX
 

drivers/pinctrl/freescale/pinctrl-scu.c

···
 
 #include <linux/err.h>
 #include <linux/firmware/imx/sci.h>
+#include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/pinctrl/pinctrl.h>
 #include <linux/platform_device.h>
···
 		pin_scu->mux_mode, pin_scu->config);
 }
 EXPORT_SYMBOL_GPL(imx_pinctrl_parse_pin_scu);
+
+MODULE_AUTHOR("Dong Aisheng <[e-mail]>");
+MODULE_DESCRIPTION("NXP i.MX SCU common pinctrl driver");
+MODULE_LICENSE("GPL v2");