add prebuilts of avbtool and mkdtimg for x15 master builds

Change-Id: Ie09fec0cdfd014548c9ed877fe5f6869b573f266
Signed-off-by: Yongqin Liu <yongqin.liu@linaro.org>
6 files changed
tree: f4afd78d58cc8dde39485f0b14fd736ecedfb273
  1. host/
  2. .gitreview