pinctrl: imx28: make it explicitly non-modular

pinctrl: imx28: make it explicitly non-modular

The Kconfig currently controlling compilation of this code is:

drivers/pinctrl/freescale/Kconfig:config PINCTRL_IMX28
drivers/pinctrl/freescale/Kconfig:	bool

...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.

We explicitly disallow a driver unbind, since that doesn't have a
sensible use case anyway, and it allows us to drop the ".remove"
code for non-modular drivers.

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

Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.

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: Linus Walleij <linus.walleij@linaro.org>
Cc: Shawn Guo <shawn.guo@linaro.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>