ARM: s3c24xx: get rid of custom <mach/gpio.h>

ARM: s3c24xx: get rid of custom <mach/gpio.h>

This isolates the custom S3C24xx GPIO definition table to
<linux/platform_data/gpio-samsung-s3x24xx.h> as this is
used in a few different places in the kernel, removing the
need to depend on the implicit inclusion of <mach/gpio.h>
from <linux/gpio.h> and thus getting rid of a few nasty
cross-dependencies.

We also delete the nifty CONFIG_S3C24XX_GPIO_EXTRA stuff.
The biggest this can ever be for the S3C24XX is
CONFIG_S3C24XX_GPIO_EXTRA = 128, and then for CPU_S3C2443 or
CPU_S3C2416 32*12 GPIOs are added, so 32*12+128 = 512
is the absolute roof value on this platform. So we set
the size of ARCH_NR_GPIO to this and the GPIOs array will
fit any S3C24XX platform, as per pattern from other archs.

ChangeLog v2->v3:
- Move the movement of the S3C64XX gpio.h file out of
  this patch and into the follow-up patch where it belongs.
ChangeLog v1->v2:
- Added an #ifdef ARCH_S3C24XX around the header inclusion
  in drivers/gpio/gpio-samsung.c as we would otherwise
  have colliding definitions when compiling S3C64XX.
- Rename inclusion guard in the header file.

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