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/samsung/smdk6400/config.mk b/board/samsung/smdk6400/config.mk
index 4ab1d7e..90cbcf2 100644
--- a/board/samsung/smdk6400/config.mk
+++ b/board/samsung/smdk6400/config.mk
@@ -24,9 +24,9 @@
 sinclude $(OBJTREE)/board/$(BOARDDIR)/config.tmp
 
 ifndef CONFIG_NAND_SPL
-TEXT_BASE = $(RAM_TEXT)
+CONFIG_SYS_TEXT_BASE = $(RAM_TEXT)
 else
-TEXT_BASE = 0
+CONFIG_SYS_TEXT_BASE = 0
 endif
 
 LDSCRIPT := $(SRCTREE)/board/$(BOARDDIR)/u-boot-nand.lds