cros_bundle_firmware: support --bmpblk (-B) for pre-generated bitmaps

Bitmaps should be generated and verified manually instead of creation
on-the-fly.

BUG=chromium-os:18544
TEST=cros_workon start cros-devutils --host
     sudo emerge cros-devutils
     emerge-tegra2_XXX chromeos-bootimage

Change-Id: I7d3b25ab123df6e17bff0348673cfd2518daa11d
Reviewed-on: http://gerrit.chromium.org/gerrit/5205
Reviewed-by: Tom Wai-Hong Tam <waihong@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Che-Liang Chiou <clchiou@chromium.org>
2 files changed