Split hybrid statespace loop out into a separate file

This reduces dependencies for the state feedback loop so we can bake
it into the pistol grip controller.

Change-Id: Ic2769123ebe837aec0624e1e5a1eb0bcbac64431
diff --git a/y2017/control_loops/superstructure/shooter/BUILD b/y2017/control_loops/superstructure/shooter/BUILD
index a57a1a3..3f9b17e 100644
--- a/y2017/control_loops/superstructure/shooter/BUILD
+++ b/y2017/control_loops/superstructure/shooter/BUILD
@@ -26,6 +26,7 @@
     'shooter_integral_plant.h',
   ],
   deps = [
+    '//frc971/control_loops:hybrid_state_feedback_loop',
     '//frc971/control_loops:state_feedback_loop',
   ],
 )