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) dont use module.h
(3) delete module_exit related code, (4) delete MODULE_DEVICE_TABLE,
and (5) delete MODULE_LICENCE/MODULE_AUTHOR and associated tags.

For the dove driver 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_platform_driver() uses the same init level priority as
builtin_platform_driver() the init ordering remains unchanged with
this commit.

We deleted the MODULE_LICENSE etc. tags since all that information
is already contained at the top of the file in the comments.

Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: linux-gpio@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>