Add flashmap and u-boot to manifest Needed to compile the sdk BUG=b/177367546 TEST=repo init, repo sync RELEASE_NOTE=None Change-Id: Icba534904a94b8f3429f207b74e4705d7d5ada0a Reviewed-on: https://cos-review.googlesource.com/c/cos/manifest/+/34460 Tested-by: Robert Kolchmeyer <rkolchmeyer@google.com> Reviewed-by: Dexter Rivera <riverade@google.com>