update_gpu_drivers.sh: Add --usebinpkg to fetch prebuilt binaries

Current script builds drivers from source, which is inconvient, as
developers need to maintain a number of overlays for this purpose.
and potentially fragile if the chroot/build environment is not clean.

Instead, fetch graphics drivers from Google Storage prebuilts,
which are only updated on successful paladin builds.

TEST=./update_gpu_drivers.sh -n --package img-ddk
     - Does not require setting up elm board
     - Takes a few seconds to run instead of a few minutes

Change-Id: I47783dd63eb9f984aabcf3171551afaf308a4de6
Reviewed-on: https://chromium-review.googlesource.com/1350452
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed