hikey: Build boot_fat.uefi.img only if TARGET_BOOTIMAGE_USE_FAT=true

Change-Id: If3719b9412a4ea4aced2a16150c46cb86b8be185
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
diff --git a/build/tasks/boot_fat.mk b/build/tasks/boot_fat.mk
index 40cb2be..e7ddaf4 100644
--- a/build/tasks/boot_fat.mk
+++ b/build/tasks/boot_fat.mk
@@ -1,5 +1,6 @@
 ifneq ($(filter hikey%, $(TARGET_DEVICE)),)
 
+ifeq ($(TARGET_BOOTIMAGE_USE_FAT), true)
 $(PRODUCT_OUT)/boot_fat.uefi.img: $(PRODUCT_OUT)/kernel $(PRODUCT_OUT)/hi6220-hikey.dtb $(PRODUCT_OUT)/ramdisk.img
 # $@ is referring to $(PRODUCT_OUT)/boot_fat.uefi.img
 	dd if=/dev/zero of=$@ bs=512 count=98304
@@ -10,5 +11,6 @@
 	mcopy -i $@ $(PRODUCT_OUT)/ramdisk.img ::ramdisk.img
 
 droidcore: $(PRODUCT_OUT)/boot_fat.uefi.img
+endif
 
 endif