Update example in docs to use new lookupBus function.
Update example in docs to use new lookupBus function.

openxc/vi-firmware,ene-ilies/vi-firmware,ene-ilies/vi-firmware,mgiannikouris/vi-firmware,openxc/vi-firmware,openxc/vi-firmware,ene-ilies/vi-firmware,openxc/vi-firmware,mgiannikouris/vi-firmware,mgiannikouris/vi-firmware,mgiannikouris/vi-firmware,ene-ilies/vi-firmware