ARM: S3C[24|64]xx: move includes back under <mach/> scope

When refactoring and breaking out the includes for the
machine-specific GPIO configuration, two files were created
in <linux/platform_data/gpio-samsung-s3c[24|64]xx.h>, but as
that namespace shall be used for defining data exchanged
between machines and drivers, using it for these broad macros
and config settings is wrong.

Move the headers back into the machine-local
<mach/gpio-samsung.h> file and think about the next step.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: linux-samsung-soc@vger.kernel.org
Acked-by: Mark Brown <broonie@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>