Change tool "fmap_decode" to "mosys"

The fmap_decode tool from flashmap project is deprecated.
mosys provides more functionality and fit better into the
host environment.

BUG=chromium-os:6264
TEST=manually

Change-Id: I513d36c8a8f657fdb4cb10d08a867876c32d36b6

Review URL: http://codereview.chromium.org/3388002
2 files changed