gpio: pl061: make explicitly non-modular

The Kconfig for this driver is currently:

config GPIO_PL061
        bool "PrimeCell PL061 GPIO support"

...meaning that it currently is not being built as a module by anyone.
Lets remove the couple traces of modularity, so that when reading the
driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

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

Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: linux-gpio@vger.kernel.org
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>