only build arch specific raid6 routines on the arch they run on.

index 8a38102..8549927 100644
@@ -1,18 +1,23 @@
 obj-$(CONFIG_RAID6_PQ)	+= raid6_pq.o
 
 raid6_pq-y	+= algos.o recov.o tables.o int1.o int2.o int4.o \
-		   int8.o int16.o int32.o altivec1.o altivec2.o altivec4.o \
-		   altivec8.o mmx.o sse1.o sse2.o
-hostprogs-y	+= mktables
+		   int8.o int16.o int32.o
 
-quiet_cmd_unroll = UNROLL  $@
-      cmd_unroll = $(AWK) -f$(srctree)/$(src)/unroll.awk -vN=$(UNROLL) \
-                   < $< > $@ || ( rm -f $@ && exit 1 )
+ifeq ($(CONFIG_X86),y)
+raid6_pq-y	+= mmx.o sse1.o sse2.o
+endif
 
 ifeq ($(CONFIG_ALTIVEC),y)
+raid6_pq-y	+=  altivec1.o altivec2.o altivec4.o altivec8.o
 altivec_flags := -maltivec -mabi=altivec
 endif
 
+hostprogs-y	+= mktables
+
+quiet_cmd_unroll = UNROLL  $@
+      cmd_unroll = $(AWK) -f$(srctree)/$(src)/unroll.awk -vN=$(UNROLL) \
+                   < $< > $@ || ( rm -f $@ && exit 1 )
+
 targets += int1.c
 $(obj)/int1.c:   UNROLL := 1
 $(obj)/int1.c:   $(src)/int.uc $(src)/unroll.awk FORCE