Rename CONFIG_SYS_TEXT_BASE to CONFIG_TEXT_BASE

The current name is inconsistent with SPL which uses CONFIG_SPL_TEXT_BASE
and this makes it imposible to use CONFIG_VAL().

Rename it to resolve this problem.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/cobra5272/README b/board/cobra5272/README
index 1dad7e3..ac62e55 100644
--- a/board/cobra5272/README
+++ b/board/cobra5272/README
@@ -89,9 +89,9 @@
 	=> u-boot as single bootloader starting from flash
 
 
-	in board/cobra5272/config.mk CONFIG_SYS_TEXT_BASE should be
+	in board/cobra5272/config.mk CONFIG_TEXT_BASE should be
 
-		CONFIG_SYS_TEXT_BASE = 0xffe00000
+		CONFIG_TEXT_BASE = 0xffe00000
 
 	=> linking address for u-boot as single bootloader stored in flash
 
@@ -128,9 +128,9 @@
 	=> u-boot as RAM version, chainloaded by another bootloader or using bdm cable
 
 
-	in board/cobra5272/config.mk CONFIG_SYS_TEXT_BASE should be
+	in board/cobra5272/config.mk CONFIG_TEXT_BASE should be
 
-		CONFIG_SYS_TEXT_BASE = 0x00020000
+		CONFIG_TEXT_BASE = 0x00020000
 
 	=> target linking address for RAM