Add support to build mutiple boards for binutils/gcc.

Now you can specify multiple boards in one command line like this
./build_tool.py --board='x86-alex,lumpy'

TEST=None
BUG=None

Change-Id: Idac899bb225ce51eab922f5ab0b08b36ce7b0e20
Reviewed-on: https://chrome-internal-review.googlesource.com/161923
Reviewed-by: Luis Lozano <llozano@chromium.org>
Commit-Queue: Han Shen <shenhan@google.com>
Tested-by: Han Shen <shenhan@google.com>
1 file changed