LU-16205 sec: reserve flag for fid2path for encrypted files

LU-16205 sec: reserve flag for fid2path for encrypted files

Reserve OBD_CONNECT2_ENCRYPT_FID2PATH connection flag for fid2path
support for encrypted files.
This connection flag is required so that newer servers continue to
return -ENODATA to older clients.

Lustre-change: https://review.whamcloud.com/49028
Lustre-commit: 6f74bb60ff6c58f4a2647556124c501100330f4c

Test-Parameters: trivial
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I505b90a061687a7ef481adacca98908c96e487be
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/49897
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>