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>

examples/standalone/Makefile

@@ -95,7 +95,7 @@ $(LIB):	$(obj).depend $(LIBOBJS)
 
 $(ELF):
 $(obj)%:	$(obj)%.o $(LIB)
-		$(LD) -g -Ttext $(STANDALONE_LOAD_ADDR) \
+		$(LD) -g -Ttext $(CONFIG_STANDALONE_LOAD_ADDR) \
 			-o $@ -e $(SYM_PREFIX)$(notdir $(<:.o=)) $< $(LIB) \
 			-L$(gcclibdir) -lgcc