Move aos/controls to frc971/control_loops

Also put what was aos/controls/control_loops.fbs in y2012/control_loops
because that's the only user.

Change-Id: I8f402b0708103077e135a41e55ef5e4f23681d87
Signed-off-by: James Kuszmaul <jabukuszmaul@gmail.com>
diff --git a/y2019/BUILD b/y2019/BUILD
index 64d825e..ec777e3 100644
--- a/y2019/BUILD
+++ b/y2019/BUILD
@@ -65,7 +65,7 @@
         "//aos:init",
         "//aos:make_unique",
         "//aos:math",
-        "//aos/controls:control_loop",
+        "//frc971/control_loops:control_loop",
         "//aos/events:shm_event_loop",
         "//aos/logging",
         "//frc971/input:robot_state_fbs",