Replace SoC specific GPIO functions with the gpiolib API. The LED
gpios are freed right after they are initially configured so they
can be acquired in the s3c24xx_led driver.

This change is required for converting the s3c24xx_led driver
to the gpiolib API.
Signed-off-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>