arch:exynos: boot mode: add get_boot_mode(), code cleanup

This patch introduces code clean-up for exynos boot mode check.
It includes:
- removal of typedef: boot_mode
- move the boot mode enum to arch-exynos/power.h
- add bootmode for sequence: eMMC 4.4 ch4 / SD ch2
- add new function: get_boot_mode() for OM[5:1] pin check
- update spl boot code

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>

Changes v5:
- exynos: boot mode: add missing bootmode (1st:EMMC 4.4 / 2nd:SD ch2)

Changes v6:
- none

changes v7:
- change boot mode name: BOOT_MODE_MMC to BOOT_MODE_SD
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
diff --git a/arch/arm/cpu/armv7/exynos/spl_boot.c b/arch/arm/cpu/armv7/exynos/spl_boot.c
index 7916630..658e4cb 100644
--- a/arch/arm/cpu/armv7/exynos/spl_boot.c
+++ b/arch/arm/cpu/armv7/exynos/spl_boot.c
@@ -20,7 +20,6 @@
 #include "clock_init.h"
 
 DECLARE_GLOBAL_DATA_PTR;
-#define OM_STAT         (0x1f << 1)
 
 /* Index into irom ptr table */
 enum index {
@@ -184,7 +183,7 @@
 */
 void copy_uboot_to_ram(void)
 {
-	enum boot_mode bootmode = BOOT_MODE_OM;
+	unsigned int bootmode = BOOT_MODE_OM;
 
 	u32 (*copy_bl2)(u32 offset, u32 nblock, u32 dst) = NULL;
 	u32 offset = 0, size = 0;
@@ -207,7 +206,7 @@
 #endif
 
 	if (bootmode == BOOT_MODE_OM)
-		bootmode = readl(samsung_get_base_power()) & OM_STAT;
+		bootmode = get_boot_mode();
 
 	switch (bootmode) {
 #ifdef CONFIG_SPI_BOOTING
@@ -216,7 +215,7 @@
 		exynos_spi_copy(param->uboot_size, CONFIG_SYS_TEXT_BASE);
 		break;
 #endif
-	case BOOT_MODE_MMC:
+	case BOOT_MODE_SD:
 		offset = BL2_START_OFFSET;
 		size = BL2_SIZE_BLOC_COUNT;
 		copy_bl2 = get_irom_func(MMC_INDEX);