hikey960: Use kernel 4.9 by default

Bug: 38204302
Test: Manual

Change-Id: I73eb02358ebd57533a8e76e0fcd74e67d153e53b
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
diff --git a/hikey960.mk b/hikey960.mk
index 0245c36..521321b 100644
--- a/hikey960.mk
+++ b/hikey960.mk
@@ -1,5 +1,5 @@
 ifndef TARGET_KERNEL_USE
-TARGET_KERNEL_USE=4.4
+TARGET_KERNEL_USE=4.9
 endif
 TARGET_PREBUILT_KERNEL := device/linaro/hikey-kernel/Image.gz-hikey960-$(TARGET_KERNEL_USE)
 TARGET_PREBUILT_DTB := device/linaro/hikey-kernel/hi3660-hikey960.dtb-$(TARGET_KERNEL_USE)