gpio: tc3589x: make explicitly non-modular

The Kconfig currently controlling compilation of this code is:

drivers/gpio/Kconfig:config GPIO_TC3589X
drivers/gpio/Kconfig: bool "TC3589X GPIOs"

...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: Linus Walleij <[e-mail]>
Cc: Alexandre Courbot <[e-mail]>
Cc: Rabin Vincent <[e-mail]>
Cc: Hanumath Prasad <[e-mail]>
Cc: [e-mail]
Signed-off-by: Paul Gortmaker <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/gpio/gpio-tc3589x.c

···
  * Author: Rabin Vincent <[e-mail]> for ST-Ericsson
  */
 
-#include <linux/module.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
···
 	return platform_driver_register(&tc3589x_gpio_driver);
 }
 subsys_initcall(tc3589x_gpio_init);
-
-static void __exit tc3589x_gpio_exit(void)
-{
-	platform_driver_unregister(&tc3589x_gpio_driver);
-}
-module_exit(tc3589x_gpio_exit);
-
-MODULE_LICENSE("GPL v2");
-MODULE_DESCRIPTION("TC3589x GPIO driver");
-MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");