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/mx1fs2/config.mk b/board/mx1fs2/config.mk
index 59ab542..eb4d046 100644
--- a/board/mx1fs2/config.mk
+++ b/board/mx1fs2/config.mk
@@ -1,10 +1,10 @@
 #
 # This config file is used for compilation of IMX sources
 #
-# You might change location of U-Boot in memory by setting right TEXT_BASE.
+# You might change location of U-Boot in memory by setting right CONFIG_SYS_TEXT_BASE.
 # This allows for example having one copy located at the end of ram and stored
 # in flash device and later on while developing use other location to test
 # the code in RAM device only.
 #
 
-TEXT_BASE = 0x08f00000
+CONFIG_SYS_TEXT_BASE = 0x08f00000