AP_HAL: disable float print methods for non FPU controllers

libraries/AP_HAL/utility/print_vprintf.cpp

@@ -157,6 +157,7 @@ void print_vprintf(AP_HAL::BetterStream *s, const char *fmt, va_list ap)
                 break;
             } while ((c = *fmt++) != 0);
 
+#if CONFIG_HAL_BOARD != HAL_BOARD_CHIBIOS || __FPU_PRESENT
             /*
              * Handle floating-point formats E, F, G, e, f, g.
              */
@@ -349,7 +350,7 @@ flt_oper:
 
                 goto tail;
             }
-
+#endif //#if CONFIG_HAL_BOARD != HAL_BOARD_CHIBIOS || __FPU_PRESENT
             /*
              * Handle string formats c, s, S.
              */