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/gth2/config.mk b/board/gth2/config.mk
index 2bc1338..c905049 100644
--- a/board/gth2/config.mk
+++ b/board/gth2/config.mk
@@ -26,16 +26,16 @@
 #
 
 ifeq ($(TBASE),0)
-TEXT_BASE = 0
+CONFIG_SYS_TEXT_BASE = 0
 else
 ifeq ($(TBASE),1)
-TEXT_BASE = 0xbfc10070
+CONFIG_SYS_TEXT_BASE = 0xbfc10070
 else
 ifeq ($(TBASE),2)
-TEXT_BASE = 0xbfc30070
+CONFIG_SYS_TEXT_BASE = 0xbfc30070
 else
 ## Only to make ordinary make work
-TEXT_BASE = 0x90000000
+CONFIG_SYS_TEXT_BASE = 0x90000000
 endif
 endif
 endif