Make STANDALONE_LOAD_ADDR configurable per board

Rename STANDALONE_LOAD_ADDR into CONFIG_STANDALONE_LOAD_ADDR
and allow that the architecture-specific default value gets
overwritten by defining the value in the board header file.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Shinya Kuribayashi <skuribay@ruby.dti.ne.jp>
Cc: Daniel Hellstrom <daniel@gaisler.com>
Cc: Tsi Chung Liew <tsi-chung.liew@freescale.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/README b/README
index c128a6c..c9fedd8 100644
--- a/README
+++ b/README
@@ -1997,6 +1997,14 @@
 		example, some LED's) on your board. At the moment,
 		the following checkpoints are implemented:
 
+- Standalone program support:
+		CONFIG_STANDALONE_LOAD_ADDR
+
+		This option allows to define board specific values
+		for the address where standalone program gets loaded,
+		thus overwriting the architecutre dependent default
+		settings.
+
 Legacy uImage format:
 
   Arg	Where			When