factory_test_tools: support write protection for ARM

The RO/RW layout is different for ARM/x86, so we must trust FMAP
to build the write protection layout.

TEST=on x86, gft_wpfw.py bios # seeing rw|ro by FMAP
     on x86, gft_wpfw.py ec # seeing ro|rw by FMAP
     assuming ARM will contain correct FMAP so the behavior is correct.
     gooftool --wpfw # success
     gooftool --verify_hwid --db_path DB --wpfw --verbose # seeing wpfw avoids reading EC/BIOS firmware again

Change-Id: Idb015522f4c3922f476beb43763107be416aa45b


Review URL: http://codereview.chromium.org/6788005
2 files changed