Blackfin: move ALL += u-boot.ldr to blackfin_config.mk

The way the ALL variable is used allows for config.mk's to add more
targets themselves without having to clutter up the top level Makefile.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/Makefile b/Makefile
index acec1a0..bcc81c9 100644
--- a/Makefile
+++ b/Makefile
@@ -306,10 +306,8 @@
 #########################################################################
 #########################################################################
 
+# Always append ALL so that arch config.mk's can add custom ones
 ALL += $(obj)u-boot.srec $(obj)u-boot.bin $(obj)System.map $(U_BOOT_NAND) $(U_BOOT_ONENAND)
-ifeq ($(ARCH),blackfin)
-ALL += $(obj)u-boot.ldr
-endif
 
 all:		$(ALL)