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/flight_common.h

@@ -0,0 +1,24 @@
+#pragma once
+
+enum {
+    AI_ROLL = 0,
+    AI_PITCH,
+} angle_index_t;
+
+#define ANGLE_INDEX_COUNT 2
+
+extern int16_t angle[ANGLE_INDEX_COUNT]; // see angle_index_t
+
+enum {
+    GI_ROLL = 0,
+    GI_PITCH,
+    GI_YAW
+} gyro_index_t;
+
+#define GYRO_INDEX_COUNT 3
+
+extern int16_t gyroData[GYRO_INDEX_COUNT]; // see gyro_index_t
+extern int16_t gyroZero[GYRO_INDEX_COUNT]; // see gyro_index_t
+
+extern int16_t gyroADC[XYZ_AXIS_COUNT], accADC[XYZ_AXIS_COUNT], accSmooth[XYZ_AXIS_COUNT];
+extern int32_t accSum[XYZ_AXIS_COUNT];