gpio: vf610: drop unused MODULE_ tags from non-modular code

The Kconfig currently controlling compilation of this code is:

drivers/gpio/Kconfig:config GPIO_VF610
drivers/gpio/Kconfig:   def_bool y

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

Lets remove the couple traces of modular infrastructure use, so that
when reading the driver there is no doubt it is builtin-only.

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

We don't replace module.h with init.h since the file already has that.

Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: linux-gpio@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>