ppc4xx: Cleanup for partial linking and --gc-sections

This commit adapts 4xx boards for partial linking with --gc-sections.

Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Stefan Roese <sr@denx.de>
Cc: Tirumala Marri <tmarri@apm.com>
Cc: David Updegraff <dave@cray.com>
Cc: Matthias Fuchs <matthias.fuchs@esd-electronics.com>
Cc: Dirk Eibach <eibach@gdsys.de>
Cc: Larry Johnson <lrj@acm.org>
Cc: Peter De Schrijver <p2@mind.be>
Cc: Niklaus Giger <niklaus.giger@netstal.com>
Cc: Daniel Poirot <dan.poirot@windriver.com>
Acked-by: Stefan Roese <sr@denx.de>
diff --git a/board/amirix/ap1000/Makefile b/board/amirix/ap1000/Makefile
index fdf6145..fe7a6a2 100644
--- a/board/amirix/ap1000/Makefile
+++ b/board/amirix/ap1000/Makefile
@@ -32,7 +32,9 @@
 OBJS	:= $(addprefix $(obj),$(COBJS))
 SOBJS	:= $(addprefix $(obj),$(SOBJS))
 
-$(LIB):	$(OBJS) $(SOBJS)
+all:	$(LIB) $(SOBJS)
+
+$(LIB):	$(OBJS)
 	$(call cmd_link_o_target, $^)
 
 clean: