Bluetooth: AMP: Physical link struct and helpers

Define physical link structures. Physical links are represented by
hci_conn structure. For BR/EDR we use type ACL_LINK and for AMP
we use AMP_LINK.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index ccc08e5..77b6a19 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -207,6 +207,7 @@
 #define ESCO_LINK	0x02
 /* Low Energy links do not have defined link type. Use invented one */
 #define LE_LINK		0x80
+#define AMP_LINK	0x81
 
 /* LMP features */
 #define LMP_3SLOT	0x01