LU-6599 header: Change erroneous GPLv3 header to GPLv2

LU-6599 header: Change erroneous GPLv3 header to GPLv2

The template for lustre_dlm_flags.h was including default
gpl definition which happened to be v3, and should have been v2.

Update the header to reflect that.
Also while we are at it, drop the whole autogeneration completely,
it was not really used and is no longer valid.

Change-Id: Id249566b71f77ecbf79a13c711f8d3ab72ca3679
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Reviewed-on: http://review.whamcloud.com/14797
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>