hammerhead: update prebuilt kernel [DO NOT MERGE] am: 79297c72b9  -s ours am: 20b259cbbf
am: 490968f3b8  -s ours

* commit '490968f3b83736fba076bba673cf19466f41d119':
  hammerhead: update prebuilt kernel [DO NOT MERGE]
tree: f0cd38b301d484d703b61094540fb09640bc2c43
  1. zImage-dtb