nvmet: Add 'sq' argument to alloc_ctrl_args

For secure concatenation the result of the TLS handshake will be
stored in the 'sq' struct, so add it to the alloc_ctrl_args struct.

Cc: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Keith Busch <kbusch@kernel.org>