hikey-kernel: Update prebuilt kernel to 4.1.15 (d71f3d2) am: d29bfaf422
am: 003a83eef7

* commit '003a83eef730d0c3dcbfe7d83a2370acb0c1b1d8':
  hikey-kernel: Update prebuilt kernel to 4.1.15 (d71f3d2)

Change-Id: I297b1e3805a8bae80dd51499613716264cf8a412