Crossfire 2 - Power Distribution mount

a mount for an Arris CC3D power distribution board: http://www.arrishobby.com/arris-power-distribution-board-pdb-with-osd-bec-output-5v-12v-3a-lc-filter-for-cc3c-naze32-f3-p-3314

use small nylon offset to allow mounting to crossfire 2 top plate.