Better defaults for posix SITL

posix-configs/SITL/init/rcS_gazebo_iris

@@ -26,6 +26,8 @@ param set COM_DISARM_LAND 3
 param set NAV_ACC_RAD 12.0
 param set RTL_RETURN_ALT 30.0
 param set RTL_DESCEND_ALT 10.0
+param set RTL_LAND_DELAY 0
+param set MIS_TAKEOFF_ALT 2.5
 param set MC_ROLLRATE_P 0.25
 param set MC_PITCHRATE_P 0.25
 param set MC_PITCH_P 5

posix-configs/SITL/init/rcS_gazebo_iris_opt_flow

@@ -26,10 +26,13 @@ param set COM_DISARM_LAND 3
 param set NAV_ACC_RAD 12.0
 param set RTL_RETURN_ALT 30.0
 param set RTL_DESCEND_ALT 10.0
+param set RTL_LAND_DELAY 0
+param set MIS_TAKEOFF_ALT 2.5
 param set MC_ROLLRATE_P 0.25
 param set MC_PITCHRATE_P 0.25
 param set MC_PITCH_P 5
 param set MC_ROLL_P 5
+param set MPC_XY_VEL_P 0.05
 rgbledsim start
 tone_alarm start
 gyrosim start

posix-configs/SITL/init/rcS_jmavsim_iris

@@ -35,7 +35,8 @@ param set COM_DISARM_LAND 3
 param set NAV_ACC_RAD 2.0
 param set RTL_RETURN_ALT 30.0
 param set RTL_DESCEND_ALT 10.0
-param set MIS_TAKEOFF_ALT 5.0
+param set RTL_LAND_DELAY 0
+param set MIS_TAKEOFF_ALT 2.5
 param set MPC_HOLD_MAX_Z 2.0
 param set MPC_HOLD_XY_DZ 0.1
 param set MPC_HOLD_Z_DZ 0.1