Bluetooth: hci_ll: Convert to use h4_recv_buf helper

The HCILL or eHCILL protocol from TI is actually an H:4 protocol with a
few extra events and thus can also use the h4_recv_buf helper. Instead
of open coding the same funtionality add the extra events to the packet
description table and use h4_recv_buf.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
index 149a38e..b83d12a 100644
--- a/drivers/bluetooth/Kconfig
+++ b/drivers/bluetooth/Kconfig
@@ -147,6 +147,7 @@
 config BT_HCIUART_LL
 	bool "HCILL protocol support"
 	depends on BT_HCIUART_SERDEV
+	select BT_HCIUART_H4
 	help
 	  HCILL (HCI Low Level) is a serial protocol for communication
 	  between Bluetooth device and host. This protocol is required for