Add mfgtools

This builds uuu to flash the devkit images

jobs.yml

@@ -38,6 +38,11 @@ librem5-devkit-tools:
   archs: ['amd64']
   dists: ['buster']
   branch: master
+mfgtools:
+  url: https://source.puri.sm/Librem5/mfgtools
+  archs: ['amd64']
+  dists: ['buster']
+  branch: pureos/purple
 modemmanager:
   url: https://source.puri.sm/Librem5/ModemManager.git
   dists: ['buster']