Bluetooth: hci_uart: Introduce h4_recv_buf helper function

The h4_recv_buf helper function can be used for receiving H:4 packets
out of a TTY stream. It is self-contained and allows for reuse by all
HCI UART protocols.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h
index 79bbcef..53b3292 100644
--- a/drivers/bluetooth/hci_uart.h
+++ b/drivers/bluetooth/hci_uart.h
@@ -99,6 +99,9 @@
 #ifdef CONFIG_BT_HCIUART_H4
 int h4_init(void);
 int h4_deinit(void);
+
+struct sk_buff *h4_recv_buf(struct hci_dev *hdev, struct sk_buff *skb,
+			    const unsigned char *buffer, int count);
 #endif
 
 #ifdef CONFIG_BT_HCIUART_BCSP