Revert "FROMGIT: kheaders: use 'tar' instead of 'cpio' for copying files"

This reverts commit 0b415945.

The clean version of commit 82a1978d ("kheaders: use 'tar' instead
of 'cpio' for copying files") will be merged instead. The --dereference
flag added manually will be implemented in a separate commit.

Cc: Yifan Hong <elsk@google.com>
Change-Id: I78fb0e451bb8c3431c04d50bb2542a4a24a62421
Signed-off-by: Carlos Llamas <cmllamas@google.com>