[POWERPC] Walnut zImage wrapper

Add zImage wrapper for walnut board

Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 2766069..fd16577 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -49,7 +49,7 @@
 src-plat := of.c cuboot-83xx.c cuboot-85xx.c holly.c \
 		cuboot-ebony.c treeboot-ebony.c prpmc2800.c \
 		ps3-head.S ps3-hvcall.S ps3.c treeboot-bamboo.c cuboot-8xx.c \
-		cuboot-pq2.c cuboot-sequoia.c
+		cuboot-pq2.c cuboot-sequoia.c treeboot-walnut.c
 src-boot := $(src-wlib) $(src-plat) empty.c
 
 src-boot := $(addprefix $(obj)/, $(src-boot))
@@ -148,6 +148,7 @@
 image-$(CONFIG_EBONY)			+= treeImage.ebony cuImage.ebony
 image-$(CONFIG_BAMBOO)			+= treeImage.bamboo
 image-$(CONFIG_SEQUOIA)			+= cuImage.sequoia
+image-$(CONFIG_WALNUT)			+= treeImage.walnut
 endif
 
 # For 32-bit powermacs, build the COFF and miboot images