Add build-kernel.sh script

This patch moves the kernel rebuild script from external/qemu/distrib/
to prebuilts/qemu-kernel/, for two reasons:

- It's logical, captain!

- external/qemu was removed from aosp/master and downstream branches
  while aosp/studio-1.2-dev doesn't provide all target toolchain
  binaries required to build the kernel.

In other words, the instructions to rebuild emulator kernel images
are now to use

  $AOSP/prebuilts/qemu-kernel/build-kernel.sh [options]

Where $AOSP points to a checkout of aosp/master.

Change-Id: I224618db8cc03cedcaabaee3fd5832dfdd5adb4a
12 files changed
tree: 770a767590888b20178b4adff19758b1497c401f
  1. arm/
  2. arm64/
  3. build-kernel.sh
  4. kernel-toolchain/
  5. mips/
  6. x86/
  7. x86_64/