SITL: added betaflight-rev-x frame

libraries/SITL/SIM_Frame.cpp

@@ -49,6 +49,15 @@ static Motor quad_bf_x_motors[] =
     Motor(AP_MOTORS_MOT_4,  -45, AP_MOTORS_MATRIX_YAW_FACTOR_CW, 4),
 };
 
+// motor order to match betaflight conventions, reversed direction
+static Motor quad_bf_x_rev_motors[] =
+{
+    Motor(AP_MOTORS_MOT_1,  135, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 2),
+    Motor(AP_MOTORS_MOT_2,   45, AP_MOTORS_MATRIX_YAW_FACTOR_CW,  1),
+    Motor(AP_MOTORS_MOT_3, -135, AP_MOTORS_MATRIX_YAW_FACTOR_CW,  3),
+    Motor(AP_MOTORS_MOT_4,  -45, AP_MOTORS_MATRIX_YAW_FACTOR_CCW, 4),
+};
+
 // motor order to match DJI conventions
 // See: https://forum44.djicdn.com/data/attachment/forum/201711/26/172348bppvtt1ot1nrtp5j.jpg
 static Motor quad_dji_x_motors[] =
@@ -190,6 +199,7 @@ static Frame supported_frames[] =
     Frame("quad",      4, quad_plus_motors),
     Frame("copter",    4, quad_plus_motors),
     Frame("x",         4, quad_x_motors),
+    Frame("bfxrev",    4, quad_bf_x_rev_motors),
     Frame("bfx",       4, quad_bf_x_motors),
     Frame("djix",      4, quad_dji_x_motors),
     Frame("cwx",       4, quad_cw_x_motors),