ARM: S3C64XX: Update for conversion to SAMSUNG_GPIO_EXTRA

The conversion of the S3C64XX GPIOs to the generic Samsung GPIOs mean that
rather than using the previous S3C24XX_GPIO_EXTRA configuration the driver
now uses SAMSUNG_GPIO_EXTRA.

Since SAMSUNG_GPIO_EXTRA requires the arch to include the extra space in
ARCH_NR_GPIOs add it on to BOARD_NR_GPIOs (in case boards are relying on
the existing reservation).

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>