bullhead: update prebuilt kernel [ DO NOT MERGE ] am: d4f83571ad  -s ours am: 1a2a394f58 am: a604fff0ad am: 97cb890834
am: 50565ca1d1  -s ours

Change-Id: Iae9e02b36f529148043c8376f090b32ef0e32ad7
tree: 854c3e8c11da9fbc8dbb684f52febc9d3011285f
  1. Image.gz-dtb
  2. Image_treble.gz-dtb