Allow blobs to have a list of contents
Allow blobs to have a list of contents

Rather than the ad-hoc approach of defining composite binaries like
boot+dtb, support having a list of binaries for each blob.

BUG=chromium-os:32034
TEST=manual
$ FEATURES=test emerge-daisy cros-devutils
Then emerge-daisy chromeos-bootimage
Boot resulting image

Change-Id: I38f7feb36628c4d8ed0da5cea351ecf4e6be095f
Reviewed-on: https://gerrit.chromium.org/gerrit/25862
Reviewed-by: Che-Liang Chiou <57969107b634cf11cb64e9d768fd46929066adab@chromium.org>
Commit-Ready: Simon Glass <c00b0378376498bd9cd974c388df8854c0131d27@chromium.org>
Tested-by: Simon Glass <c00b0378376498bd9cd974c388df8854c0131d27@chromium.org>

mgireesh05/dev-util,coreos/dev-util,mgireesh05/dev-util,marineam/coreos-dev-util,marineam/coreos-dev-util,coreos/dev-util,coreos/dev-util,mgireesh05/dev-util