LU-6142 mdt: SPDX for MetaData Target

LU-6142 mdt: SPDX for MetaData Target

Convert from verbose license text to SPDX.

Test-Parameters: trivial
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: Ib116dfc5143297a13426881d8ee91df7275b8c8c
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/57797
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>