[Bluetooth] Add basics to better support and handle eSCO links

To better support and handle eSCO links in the future a bunch of
constants needs to be added and some basic routines need to be
updated. This is the initial step.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 7c78744..8f67c8a 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -78,6 +78,7 @@
 	__u16		voice_setting;
 
 	__u16		pkt_type;
+	__u16		esco_type;
 	__u16		link_policy;
 	__u16		link_mode;
 
@@ -452,6 +453,7 @@
 #define lmp_encrypt_capable(dev)   ((dev)->features[0] & LMP_ENCRYPT)
 #define lmp_sniff_capable(dev)     ((dev)->features[0] & LMP_SNIFF)
 #define lmp_sniffsubr_capable(dev) ((dev)->features[5] & LMP_SNIFF_SUBR)
+#define lmp_esco_capable(dev)      ((dev)->features[3] & LMP_ESCO)
 
 /* ----- HCI protocols ----- */
 struct hci_proto {