greybus: es2: fix kernel-doc warnings

Fix these kernel-doc complaints:

../drivers/greybus/es2.c:79: warning: bad line:
../drivers/greybus/es2.c:100: warning: cannot understand function prototype: 'struct es2_ap_dev '
es2.c:126: warning: Function parameter or member 'cdsi1_in_use' not described in 'es2_ap_dev'

Cc: Johan Hovold <[e-mail]>
Cc: Alex Elder <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: [e-mail] (moderated for non-subscribers)
Signed-off-by: Randy Dunlap <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/greybus/es2.c

···
 };
 
 /**
- * es2_ap_dev - ES2 USB Bridge to AP structure
+ * struct es2_ap_dev - ES2 USB Bridge to AP structure
  * @usb_dev: pointer to the USB device we are.
  * @usb_intf: pointer to the USB interface we are bound to.
  * @hd: pointer to our gb_host_device structure
-
+ *
  * @cport_in: endpoint, urbs and buffer for cport in messages
  * @cport_out_endpoint: endpoint for for cport out messages
  * @cport_out_urb: array of urbs for the CPort out messages
···
  * @cport_out_urb_cancelled: array of flags indicating whether the
  *			corresponding @cport_out_urb is being cancelled
  * @cport_out_urb_lock: locks the @cport_out_urb_busy "list"
- *
+ * @cdsi1_in_use: true if cport CDSI1 is in use
  * @apb_log_task: task pointer for logging thread
  * @apb_log_dentry: file system entry for the log file interface
  * @apb_log_enable_dentry: file system entry for enabling logging