staging: lustre: obd: reserve connection flag OBD_CONNECT_FLAGS2

This is a feature for the client and server to use
obd_connect_flags2 to communicate future feature flags. The
client should set this flag whenever any flags in that field
are requested, and the server should mask unsupported features
from this field (assuming it understands OBD_CONNECT_FLAGS2).
When checking if an OBD_CONNECT2_xxxx feature is supported,
the client/server needs to firstly check if OBD_CONNECT_FLAGS2
is supported, since this field is also beyond the end of the
old obd_connect_data.

Land the connection flags to upstream client earlier for reserving
the slot to avoid potential conflict with others.

Signed-off-by: Fan Yong <fan.yong@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-7543
Reviewed-on: http://review.whamcloud.com/17647


Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Patrick Farrell <paf@cray.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>