Fix cross compiling ISA flag for oat-target.

Change-Id: I28416784552ebbb437ec52c8b421b65f7f2e24f9
diff --git a/Android.mk b/Android.mk
index 9ccb9e4..9ddd2ba 100644
--- a/Android.mk
+++ b/Android.mk
@@ -187,14 +187,14 @@
 ifeq ($(ONE_SHOT_MAKEFILE),)
 .PHONY: oat-target-$(1)
 oat-target-$(1): $(PRODUCT_OUT)/$(1) $(TARGET_BOOT_IMG_OUT) $(DEX2OAT_DEPENDENCY)
-	$(DEX2OAT) $(PARALLEL_ART_COMPILE_JOBS) --runtime-arg -Xms64m --runtime-arg -Xmx64m --boot-image=$(TARGET_BOOT_IMG_OUT) --dex-file=$(PRODUCT_OUT)/$(1) --dex-location=/$(1) --oat-file=$$(OUT_OAT_FILE) --host-prefix=$(PRODUCT_OUT)
+	$(DEX2OAT) $(PARALLEL_ART_COMPILE_JOBS) --runtime-arg -Xms64m --runtime-arg -Xmx64m --boot-image=$(TARGET_BOOT_IMG_OUT) --dex-file=$(PRODUCT_OUT)/$(1) --dex-location=/$(1) --oat-file=$$(OUT_OAT_FILE) --host-prefix=$(PRODUCT_OUT) --instruction-set=$(TARGET_ARCH)
 
 else
 .PHONY: oat-target-$(1)
 oat-target-$(1): $$(OUT_OAT_FILE)
 
 $$(OUT_OAT_FILE): $(PRODUCT_OUT)/$(1) $(TARGET_BOOT_IMG_OUT) $(DEX2OAT_DEPENDENCY)
-	$(DEX2OAT) $(PARALLEL_ART_COMPILE_JOBS) --runtime-arg -Xms64m --runtime-arg -Xmx64m --boot-image=$(TARGET_BOOT_IMG_OUT) --dex-file=$(PRODUCT_OUT)/$(1) --dex-location=/$(1) --oat-file=$$@ --host-prefix=$(PRODUCT_OUT)
+	$(DEX2OAT) $(PARALLEL_ART_COMPILE_JOBS) --runtime-arg -Xms64m --runtime-arg -Xmx64m --boot-image=$(TARGET_BOOT_IMG_OUT) --dex-file=$(PRODUCT_OUT)/$(1) --dex-location=/$(1) --oat-file=$$@ --host-prefix=$(PRODUCT_OUT) --instruction-set=$(TARGET_ARCH)
 
 endif