Bluetooth: btusb: Fix BT_HCIBTUSB_AUTOSUSPEND Kconfig option name

Fix: drivers/bluetooth/Kconfig:35:warning: multi-line strings not
supported warning.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>