Make ROOT-B 4096 blocks long to workaround recovery image padding

BUG=chrome-os-partner:15036
TEST=Build/run recovery image, verify it runs at expected speed

Change-Id: I8bd701761456a9444845ffc87b9b70f7d3f0c371
Reviewed-on: https://gerrit.chromium.org/gerrit/35226
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Commit-Ready: Liam McLoughlin <lmcloughlin@chromium.org>
Tested-by: Liam McLoughlin <lmcloughlin@chromium.org>
(cherry picked from commit 61de2dc827e7ea82149f97a26d77827b888c266e)
Reviewed-on: https://gerrit.chromium.org/gerrit/35366
Tested-by: Katie Roberts-Hoffman <katierh@chromium.org>
Reviewed-by: Ryan Cairns <rtc@chromium.org>
1 file changed