ksmbd: set v2 lease capability

[ Upstream commit 18dd1c36

 ]

Set SMB2_GLOBAL_CAP_DIRECTORY_LEASING to ->capabilities to inform server
support directory lease to client.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>