Bluetooth: Add the structure for Write Sync Train Parameters

The Write_Synchronization_Train_Parameters command configures
the Synchronization Train functionality in the BR/EDR Controller.

The Core Spec Addendum 4 adds this command in part B Connectionless
Slave Broadcast.

Bluetooth Core Specification Addendum 4 - Page 97

"7.3.90 Write Synchronization Train Parameters Command [New Section]
...
Note: The AFH_Channel_Map used in the Synchronization Train packets is
configured by the Set_AFH_Channel_Classification command and the local
channel classification in the BR/EDR Controller.

Interval_Min and Interval_Max specify the allowed range of
Sync_Train_Interval. Refer to [Vol. 2], Part B, section 2.7.2 for
a detailed description of Sync_Train_Interval. The BR/EDR Controller shall
select an interval from this range and return it in Sync_Train_Interval.
If the Controller is unable to select a value from this range, it shall
return the Invalid HCI Command Parameters (0x12) error code.

Once started (via the Start_Synchronization_Train Command) the
Synchronization Train will continue until synchronization_trainTO slots have
passed or Connectionless Slave Broadcast has been disabled."
Signed-off-by: NDohyun Pyun <dh79.pyun@samsung.com>
Signed-off-by: NC S Bhargava <cs.bhargava@samsung.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/hci.h

@@ -873,6 +873,18 @@ struct hci_rp_set_csb_data {
 
 #define HCI_OP_READ_SYNC_TRAIN_PARAMS	0x0c77
 
+#define HCI_OP_WRITE_SYNC_TRAIN_PARAMS	0x0c78
+struct hci_cp_write_sync_train_params {
+	__le16	interval_min;
+	__le16	interval_max;
+	__le32	sync_train_tout;
+	__u8	service_data;
+} __packed;
+struct hci_rp_write_sync_train_params {
+	__u8	status;
+	__le16	sync_train_int;
+} __packed;
+
 #define HCI_OP_READ_LOCAL_VERSION	0x1001
 struct hci_rp_read_local_version {
 	__u8     status;