switched from fitpc/atom to prime/linux

Also removed a few old things that had nothing reasonable to be changed
to.
diff --git a/frc971/control_loops/drivetrain/drivetrain_main.cc b/frc971/control_loops/drivetrain/drivetrain_main.cc
index e3fc306..f3f0ddd 100644
--- a/frc971/control_loops/drivetrain/drivetrain_main.cc
+++ b/frc971/control_loops/drivetrain/drivetrain_main.cc
@@ -1,6 +1,6 @@
 #include "frc971/control_loops/drivetrain/drivetrain.h"
 
-#include "aos/atom_code/init.h"
+#include "aos/linux_code/init.h"
 
 int main() {
   ::aos::Init();