Give pi user rt permission and mlock permission

Otherwise, the user can't map and lock all memory like we want.

Change-Id: I15eaa85670123b48870db8ff64cfc80e6ff887e5
diff --git a/y2020/vision/rootfs/rt.conf b/y2020/vision/rootfs/rt.conf
new file mode 100644
index 0000000..ad2c08b
--- /dev/null
+++ b/y2020/vision/rootfs/rt.conf
@@ -0,0 +1,3 @@
+pi - nice -20
+pi - rtprio 95
+pi - memlock unlimited