smb: smbdirect: introduce smbdirect_connection_idle_timer_work()

smb: smbdirect: introduce smbdirect_connection_idle_timer_work()

This is basically a copy of idle_connection_timer() in the client
and smb_direct_idle_connection_timer() in the server.
The only difference is that the server does not have logging.

Currently the callers set their own timer function after
smbdirect_socket_prepare_create(), but that will change
in the next steps...

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>