Bluetooth: mgmt: Implement support for passkey notification

This patch adds support for Secure Simple Pairing with devices that have
KeyboardOnly as their IO capability. Such devices will cause a passkey
notification on our side and optionally also keypress notifications.
Without this patch some keyboards cannot be paired using the mgmt
interface.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
diff --git a/include/net/bluetooth/mgmt.h b/include/net/bluetooth/mgmt.h
index 1b48eff..22980a7 100644
--- a/include/net/bluetooth/mgmt.h
+++ b/include/net/bluetooth/mgmt.h
@@ -478,3 +478,10 @@
 struct mgmt_ev_device_unpaired {
 	struct mgmt_addr_info addr;
 } __packed;
+
+#define MGMT_EV_PASSKEY_NOTIFY		0x0017
+struct mgmt_ev_passkey_notify {
+	struct mgmt_addr_info addr;
+	__le32	passkey;
+	__u8	entered;
+} __packed;