Bluetooth: Add defines for LE initiator filter policy

This patch adds defines for the initiator filter policy parameter values
of the HCI_LE_Create_Connection command. They will be used in a
subsequent patch to check whether we should have a timeout for the
connection attempt or not.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>