Merge "hikey.mk/hikey960.mk: add support for android-mainline kernel" am: d90872832e am: d1d0203a85 am: a5a5509042

Original change: https://android-review.googlesource.com/c/device/linaro/hikey/+/1509788

Change-Id: Ic83a37489ef50330b71d8c62cdca7847eae57dfb