hikey-kernel: Add missing syscon-reboot-mode.ko prebuilt module am: ab24429a49 am: 2a5b7d6fc8 am: bcc36e3925 am: 1445363890

Original change: https://android-review.googlesource.com/c/device/linaro/hikey-kernel/+/1398791

Change-Id: I3954b65763b7920d84072f98a5ecfc126431f948
tree: 703130dd9b051b0f64dd23f4d9c9e2d2a01e70c0
  1. hikey/
  2. hikey960/
  3. update-prebuilts.sh