hikey: Use Image-dtb instead of Image

Switch over to using Image-dtb for abootimg support

NOTE: This patch depends on the appended dtb Image-dtb
prebuilt kernel existing.

Change-Id: I9850957aa7e44f95d88ee88abcf2e329007cfd14
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
[jstultz: Reworked and split out from Haojian's original patch]
Signed-off-by: John Stultz <john.stultz@linaro.org>

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
diff --git a/device.mk b/device.mk
index ba42933..ed87bd4 100644
--- a/device.mk
+++ b/device.mk
@@ -18,7 +18,7 @@
 $(call inherit-product-if-exists, frameworks/native/build/tablet-10in-xhdpi-2048-dalvik-heap.mk)
 
 ifeq ($(TARGET_PREBUILT_KERNEL),)
-LOCAL_KERNEL := device/linaro/hikey-kernel/Image
+LOCAL_KERNEL := device/linaro/hikey-kernel/Image-dtb
 LOCAL_DTB := device/linaro/hikey-kernel/hi6220-hikey.dtb
 LOCAL_FSTAB := fstab.hikey
 else