Bluetooth: Implement set_pairable managment command

This patch implements a new set_pairable management command to control
the pairable state of local adapters. The state is represented using a
new HCI_PAIRABLE flag in the hci_dev struct.

For backwards compatibility with older user space versions the
HCI_PAIRABLE flag gets automatically set when the existence of an
adapter is reported to user space through legacy methods and the
HCI_MGMT flag is not set.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 469f8fd..f0c25b5 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -80,6 +80,7 @@
 	HCI_SETUP,
 	HCI_AUTO_OFF,
 	HCI_MGMT,
+	HCI_PAIRABLE,
 };
 
 /* HCI ioctl defines */