Rename TEXT_BASE into CONFIG_SYS_TEXT_BASE

The change is currently needed to be able to remove the board
configuration scripting from the top level Makefile and replace it by
a simple, table driven script.

Moving this configuration setting into the "CONFIG_*" name space is
also desirable because it is needed if we ever should move forward to
a Kconfig driven configuration system.

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/board/sx1/lowlevel_init.S b/board/sx1/lowlevel_init.S
index bdf812e..c1a811a 100644
--- a/board/sx1/lowlevel_init.S
+++ b/board/sx1/lowlevel_init.S
@@ -37,7 +37,7 @@
 
 
 _TEXT_BASE:
-	.word	TEXT_BASE	 /* sdram load addr from config.mk */
+	.word	CONFIG_SYS_TEXT_BASE	 /* sdram load addr from config.mk */
 
 .globl lowlevel_init
 lowlevel_init: