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/goni/config.mk b/board/samsung/goni/config.mk
index 0e9dd45..e4581ca 100644
--- a/board/samsung/goni/config.mk
+++ b/board/samsung/goni/config.mk
@@ -31,4 +31,4 @@
 # 0x30000000 to 0x35000000 (80MiB)
 # 0x40000000 to 0x50000000 (256MiB)
 #
-TEXT_BASE = 0x34800000
+CONFIG_SYS_TEXT_BASE = 0x34800000