pinctrl: sirf: make atlas7 explicitly non-modular

The Makefile currently controlling compilation of this code is:

  drivers/pinctrl/sirf/pinctrl-atlas7.o
    ---> drivers/pinctrl/sirf/Makefile:obj-y += pinctrl-atlas7.o

...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 already contained at the top of the file in the comments.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Barry Song <baohua@kernel.org>
Cc: linux-gpio@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>