Revert vendor directory to support old golang (GOPATH mode)

gomodule is still in progress to migrate for now, hence multus
team decide to keep vendor directory to support build without
gomodule.

vendor/golang.org/x/sys/unix/bluetooth_linux.go

@@ -0,0 +1,35 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Bluetooth sockets and messages
+
+package unix
+
+// Bluetooth Protocols
+const (
+	BTPROTO_L2CAP  = 0
+	BTPROTO_HCI    = 1
+	BTPROTO_SCO    = 2
+	BTPROTO_RFCOMM = 3
+	BTPROTO_BNEP   = 4
+	BTPROTO_CMTP   = 5
+	BTPROTO_HIDP   = 6
+	BTPROTO_AVDTP  = 7
+)
+
+const (
+	HCI_CHANNEL_RAW     = 0
+	HCI_CHANNEL_USER    = 1
+	HCI_CHANNEL_MONITOR = 2
+	HCI_CHANNEL_CONTROL = 3
+)
+
+// Socketoption Level
+const (
+	SOL_BLUETOOTH = 0x112
+	SOL_HCI       = 0x0
+	SOL_L2CAP     = 0x6
+	SOL_RFCOMM    = 0x12
+	SOL_SCO       = 0x11
+)