gpio-samsung: Remove now unused s3c2410_gpio* API

There is no more users of s3c2410_gpio_pullup(), s3c2410_gpio_setpin()
and s3c2410_gpio_getpin() so remove theese functions.

Signed-off-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>