Bluetooth: Handle one LE connection at the time

For now, we are able to carry out one LE connection request at the
time. So, in order to guarantee there is only one connection attempt,
we should check for LE hci_conn objects in BT_SCAN state.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
WIP: Bluetooth: Initialize some hci_conn fields in hci_connent_le instead of hci_le_create_connection.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
WIP: Bluetooth: Remove L2CAP connection timeout

This patch also don't set the l2cap channel timer if it is LE CID.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>