[POWERPC] iSeries: head_64.o needs to depend on lparmap.s

This dependency was inadvertantly removed in a previous patch
(e73aedba562d1e7777287043afb8e46131ed402e).

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/Makefile

@@ -77,6 +77,7 @@ endif
 
 ifeq ($(CONFIG_PPC_ISERIES),y)
 extra-y += lparmap.s
+$(obj)/head_64.o:	$(obj)/lparmap.s
 AFLAGS_head_64.o += -I$(obj)
 endif