uboot-phytec

buildman: Tidy up the 'cloning' message

On a machine with a lot of CPUs this prints a lot of useless lines of the
form:

   Cloning repo for thread <n>

Adjust the output so that these all appear on one line, and disappear when
the cloning is complete.

Note: This cloning is actually unnecessary and very wasteful on disk space
(about 3.5GB each time). It would be better to create symlinks.

Signed-off-by: Simon Glass <sjg@chromium.org>