Bluetooth: Notify suspend on le conn failed

When suspending, Bluetooth disconnects all connected peers devices. If
an LE connection is started but isn't completed, we will see an LE
Create Connection Cancel instead of an HCI disconnect. This just adds
a check to see if an LE cancel was the last disconnected device and wake
the suspend thread when that is the case.

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