pinctrl: vt8500: make bool drivers explicitly non-modular

None of the Kconfigs for any of these drivers are tristate, meaning
that they currently are not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the drivers there is no doubt they are builtin-only.  All
drivers get the exact same change, so they are handled in batch.

Changes are (1) use builtin_platform_driver, (2) use init.h header
(3) delete module_exit related code, (4) delete MODULE_DEVICE_TABLE,
(5) delete MODULE_LICENCE/MODULE_AUTHOR and associated tags and (6)
drop ".remove" code and prevent sysfs unbind attempts to call ".remove".

Once this is done, the shared remove function in wmt.[ch] is no longer
used and hence it is removed as well.

Since module_platform_driver() uses the same init level priority as
builtin_platform_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 etc. tags since all that information
is already contained at the top of each file in the comments.

Cc: Tony Prisk <linux@prisktech.co.nz>
Cc: Linus Walleij <linus.walleij@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>