gpio: tps6586x: make explicitly non-modular

The Kconfig currently controlling compilation of this code is:

drivers/gpio/Kconfig:config GPIO_TPS6586X
drivers/gpio/Kconfig: bool "TPS6586X GPIO"

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init was not in use by this code, the init ordering
remains unchanged with this commit.

We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.

Cc: Alexandre Courbot <[e-mail]>
Cc: Laxman Dewangan <[e-mail]>
Cc: [e-mail]
Signed-off-by: Paul Gortmaker <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/gpio/gpio-tps6586x.c

···
 #include <linux/errno.h>
 #include <linux/gpio.h>
 #include <linux/kernel.h>
-#include <linux/module.h>
+#include <linux/init.h>
 #include <linux/mfd/tps6586x.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
···
 	return platform_driver_register(&tps6586x_gpio_driver);
 }
 subsys_initcall(tps6586x_gpio_init);
-
-static void __exit tps6586x_gpio_exit(void)
-{
-	platform_driver_unregister(&tps6586x_gpio_driver);
-}
-module_exit(tps6586x_gpio_exit);
-
-MODULE_ALIAS("platform:tps6586x-gpio");
-MODULE_DESCRIPTION("GPIO interface for TPS6586X PMIC");
-MODULE_AUTHOR("Laxman Dewangan <[e-mail]>");
-MODULE_LICENSE("GPL");