[PATCH 6/8] tty: n_gsm: add missing length field in control channel commands

Observing debug output while running initator and responder using n_gsm shows all control channel commands sent by initiator are malformed - they don't include length field (3GPP TS 07.10 ver 7.2.0, 5.4.6.1). Add length field to transmitted control channel commands in the gsm_control_transmit) as

[PATCH 6/8] tty: n_gsm: add missing length field in control channel commands

Observing debug output while running initator and responder using n_gsm shows all control channel commands sent by initiator are malformed - they don't include length field (3GPP TS 07.10 ver 7.2.0, 5.4.6.1). Add length field to transmitted control channel commands in the gsm_control_transmit) as