S5P: Use accessor functions instead of SoC specific defines to access the base address

This patch is intended to prepare the other S5P SoC. (s5pc210)
If use SoC specific defines then can't share with other SoC.
So, make the accessor functions for access the base address by common way.

Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
diff --git a/board/samsung/smdkc100/smdkc100.c b/board/samsung/smdkc100/smdkc100.c
index fb466c6..bb72fd1 100644
--- a/board/samsung/smdkc100/smdkc100.c
+++ b/board/samsung/smdkc100/smdkc100.c
@@ -38,7 +38,7 @@
 	u32 smc_bw_conf, smc_bc_conf;
 
 	struct s5pc100_gpio *const gpio =
-		(struct s5pc100_gpio *)S5PC100_GPIO_BASE;
+		(struct s5pc100_gpio *)samsung_get_base_gpio();
 
 	/* gpio configuration GPK0CON */
 	gpio_cfg_pin(&gpio->gpio_k0, CONFIG_ENV_SROM_BANK, GPIO_FUNC(2));