GCS_MAVLink: move from HAL_NO_GCS to HAL_GCS_ENABLED

libraries/GCS_MAVLink/GCS.h

@@ -3,6 +3,14 @@
 // protocols.
 #pragma once
 
+#include <AP_HAL/AP_HAL_Boards.h>
+
+#ifndef HAL_GCS_ENABLED
+#define HAL_GCS_ENABLED 1
+#endif
+
+#if HAL_GCS_ENABLED
+
 #include <AP_HAL/AP_HAL.h>
 #include <AP_Common/AP_Common.h>
 #include "GCS_MAVLink.h"
@@ -31,8 +39,6 @@
 #define HAL_HIGH_LATENCY2_ENABLED !HAL_MINIMIZE_FEATURES
 #endif
 
-#ifndef HAL_NO_GCS
-
 // macros used to determine if a message will fit in the space available.
 
 void gcs_out_of_space_to_send_count(mavlink_channel_t chan);
@@ -1112,9 +1118,9 @@ void can_printf(const char *fmt, ...);
 }
 #define GCS_SEND_TEXT(severity, format, args...) can_printf(format, ##args)
 
-#else // HAL_NO_GCS
+#else // HAL_GCS_ENABLED
 // empty send text when we have no GCS
 #define GCS_SEND_TEXT(severity, format, args...)
 
-#endif // HAL_NO_GCS
+#endif // HAL_GCS_ENABLED