Final parameter interface cleanup - removed last bit of old cruft, fixed a bug on parameter update notification, cleaned up API slightly in naming

apps/drivers/mpu6000/mpu6000.cpp

@@ -55,6 +55,7 @@
 
 #include <systemlib/perf_counter.h>
 #include <systemlib/err.h>
+#include <systemlib/conversions.h>
 
 #include <nuttx/arch.h>
 #include <nuttx/clock.h>
@@ -761,20 +762,6 @@ MPU6000::measure_trampoline(void *arg)
 	dev->measure();
 }
 
-int16_t
-int16_t_from_bytes(uint8_t bytes[])
-{
-    union {
-        uint8_t    b[2];
-        int16_t    w;
-    } u;
-
-    u.b[1] = bytes[0];
-    u.b[0] = bytes[1];
-
-    return u.w;
-}
-
 void
 MPU6000::measure()
 {