Update gpio/ledring drivers so they do not include "board.h". It is now

clear what all gpio/ledring drivers need to compile and what was
unnecessarily included before.
 
In attempting this it was clear that ledring had a dependency on the
multiwii code, this was removed by passing the led status update method
the values it needs.

It also turned out that the ROLL/PITCH defines were coming from
rc_alias_e and much unrelated code is coupled to these defines.  This
commit also includes some cleanups relating to that problem.

src/board.h

@@ -21,6 +21,7 @@
 #include "drivers/system_common.h"
 #include "drivers/altimeter_common.h"
 #include "sensors_common.h"
+#include "axis.h"
 
 typedef enum {
     SENSOR_GYRO = 1 << 0, // always present