global: Migrate CONFIG_DFU_ALT et al to CFG

Perform simple renames of:
   CONFIG_DFU_ALT to CFG_DFU_ALT
   CONFIG_DFU_ALT_BOOT_EMMC to CFG_DFU_ALT_BOOT_EMMC
   CONFIG_DFU_ALT_BOOT_SD to CFG_DFU_ALT_BOOT_SD
   CONFIG_DFU_ALT_SYSTEM to CFG_DFU_ALT_SYSTEM
   CONFIG_DFU_ENV_SETTINGS to CFG_DFU_ENV_SETTINGS

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/board/samsung/odroid/odroid.c b/board/samsung/odroid/odroid.c
index 35e4cee..39a60e4 100644
--- a/board/samsung/odroid/odroid.c
+++ b/board/samsung/odroid/odroid.c
@@ -94,8 +94,8 @@
 	if (mmc_init(mmc))
 		return NULL;
 
-	alt_boot = IS_SD(mmc) ? CONFIG_DFU_ALT_BOOT_SD :
-				CONFIG_DFU_ALT_BOOT_EMMC;
+	alt_boot = IS_SD(mmc) ? CFG_DFU_ALT_BOOT_SD :
+				CFG_DFU_ALT_BOOT_EMMC;
 
 	return alt_boot;
 }