post_box_usb: Remove r1 production files, to avoid confusion
post_box_usb: Remove r1 production files, to avoid confusion

google/myelin-acorn-electron-hardware,google/myelin-acorn-electron-hardware,google/myelin-acorn-electron-hardware,google/myelin-acorn-electron-hardware,google/myelin-acorn-electron-hardware,google/myelin-acorn-electron-hardware