Bluetooth: Remove unneeded commands for suspend

During suspend, there are a few scan enable and set event filter
commands that don't need to be sent unless there are actual BR/EDR
devices capable of waking the system. Check the HCI_PSCAN bit before
writing scan enable and use a new dev flag, HCI_EVENT_FILTER_CONFIGURED
to control whether to clear the event filter.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Archie Pusaka <apusaka@chromium.org>
Reviewed-by: Alain Michaud <alainm@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>