Currently SSHControl class has methods to copy a single file from/to DUT. In order to copy/remove several files there is need for other methods.
Patch sent to the list: http://lists.openembedded.org/pipermail/openembedded-core/2016-May/120850.html
Bug has been solved with commit: http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=eb0ab04149d4d2f3966bce7dd2060d68c6963131