Add a TODO for LPC1768's USB.
Add a TODO for LPC1768's USB.

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