Bluetooth: Modify LE window and interval for suspend

When a device is suspended, it doesn't need to be as responsive to
connection events. Increase the interval to 640ms (creating a duty cycle
of roughly 1.75%) so that passive scanning uses much less power (vs
previous duty cycle of 18.75%). The new window + interval combination
has been tested to work with HID devices (which are currently the only
devices capable of wake up).

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>