Revert "delete toolbox/r.c"

This utility is always useful during device bringup, so let's bring it
back for debug builds.

This reverts commit 8a475f7e4ae72db0a6cfe31ab46f588e89e0fc34.

Change-Id: Ic4041afe538663f1e201ee1341dee247ab0d5ba2
2 files changed