Bluetooth: Remove timeout handling from hci_cancel_le_scan

This patch moves the LE scanning timeout handling from hci_cancel_
le_scan helper to stop_discovery.

Since we want discovery code handling LE scanning timeout, we should
handle it in stop_discovery instead of hci_cancel_le_scan.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Remove LE scan work

This patch removes the LE scan work and all code related to it. We
now use the HCI request framework to enable LE scanning so the LE
scan work is no longer needed.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Change LE scanning timeout macros

Define LE scanning timeout macros in jiffies just like we do for
others timeout macros.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Bluetooth: Add LE scan type macros

This patch adds macros for active and passive LE scan type values. It
also removes the LE_SCAN_TYPE macro since it is not used anymore.

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