S5P: Exynos: Add GPIO pin numbering and rename definitions

This patch includes following changes :
* Adds gpio pin numbering support for EXYNOS SOCs.
  To have consistent 0..n-1 GPIO numbering the banks are divided
  into different parts where ever they have holes in them.

* Rename GPIO definitions from GPIO_... to S5P_GPIO_...
  These changes were done to enable cmd_gpio for EXYNOS and
  cmd_gpio has GPIO_INPUT same as s5p_gpio driver and hence
  getting a error during compilation.

* Adds support for name to gpio conversion in s5p_gpio to enable
  gpio command EXYNOS SoCs. Function has been added to asm/gpio.h
  to decode the input gpio name to gpio number.
  Example: SMDK5420 # gpio set gpa00

Signed-off-by: Leela Krishna Amudala <l.krishna@samsung.com>
Signed-off-by: Rajeshwari Shinde <rajeshwari.s@samsung.com>
Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
diff --git a/board/samsung/smdkc100/smdkc100.c b/board/samsung/smdkc100/smdkc100.c
index 860c851..e009564 100644
--- a/board/samsung/smdkc100/smdkc100.c
+++ b/board/samsung/smdkc100/smdkc100.c
@@ -21,11 +21,8 @@
 {
 	u32 smc_bw_conf, smc_bc_conf;
 
-	struct s5pc100_gpio *const gpio =
-		(struct s5pc100_gpio *)samsung_get_base_gpio();
-
 	/* gpio configuration GPK0CON */
-	s5p_gpio_cfg_pin(&gpio->k0, CONFIG_ENV_SROM_BANK, GPIO_FUNC(2));
+	gpio_cfg_pin(S5PC100_GPIO_K00 + CONFIG_ENV_SROM_BANK, S5P_GPIO_FUNC(2));
 
 	/* Ethernet needs bus width of 16 bits */
 	smc_bw_conf = SMC_DATA16_WIDTH(CONFIG_ENV_SROM_BANK);