LU-13437 uapi: add OBD_CONNECT2_GETATTR_PFID

LU-13437 uapi: add OBD_CONNECT2_GETATTR_PFID

Add OBD_CONNECT2_GETATTR_PFID connect flag to pack parent FID in
getattr request, which will be used to check whether target is
remote object, if so, don't take LOOKUP lock, otherwise client
may see stale directory entries.

Lustre-change: https://review.whamcloud.com/39289
Lustre-commit: f384a8733c41e43ebc2db3c542287a700ace8cbb
Test-parameters: trivial

Signed-off-by: Lai Siyao <lai.siyao@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Neil Brown <neilb@suse.de>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Change-Id: Ibdf880934456f255f83cd4bac9d61ab5e1ed7330
Reviewed-on: https://review.whamcloud.com/39770
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>