tty: document @dlci parameter in gsm_modem_send_initial_msc

Add missing kernel-doc entry for the @dlci parameter in
gsm_modem_send_initial_msc(), which fixes the following warning
reported by kernel-doc:

Warning: drivers/tty/n_gsm.c:4175 function parameter 'dlci' not described in 'gsm_modem_send_initial_msc'

Signed-off-by: Kriish Sharma <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/n_gsm.c

···
 /**
  * gsm_modem_send_initial_msc - Send initial modem status message
  *
- * @dlci channel
+ * @dlci: channel
  *
  * Send an initial MSC message after DLCI open to set the initial
  * modem status lines. This is only done for basic mode.