Bluetooth: increase timeout for le auto connections

This patch increases the connection timeout for LE connections that are
triggered by the advertising report to 4 seconds.

It has been observed that devices equipped with wifi+bt combo SoC fail
to create a connection with BLE devices due to their coexistence issues.
Increasing this timeout gives them enough time to complete the
connection with success.

Signed-off-by: Konrad Zapałowicz <konrad.zapalowicz@canonical.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>