Make the IMU communications more reliable

This hooks up support for the reset line and forces the chip select line
to actually change state.

Change-Id: I41427334789e373728cbb9b4327f17540aadbc33
diff --git a/aos/linux_code/init.h b/aos/linux_code/init.h
index e069b83..e34ecfd 100644
--- a/aos/linux_code/init.h
+++ b/aos/linux_code/init.h
@@ -30,6 +30,9 @@
 // Sets the current thread's realtime priority.
 void SetCurrentThreadRealtimePriority(int priority);
 
+// Sets the current thread back down to non-realtime priority.
+void UnsetCurrentThreadRealtimePriority();
+
 // Pins the current thread to CPU #number.
 void PinCurrentThreadToCPU(int number);