RPi px4_fw.config: use AERT mixer file & fix fw_pos_control_l1 start

posix-configs/rpi/px4_fw.config

@@ -11,7 +11,7 @@ sensors start
 commander start
 ekf2 start
 fw_att_control start
-fw_pos_control_l1
+fw_pos_control_l1 start
 mavlink start -u 14556 -r 1000000
 sleep 1
 mavlink stream -u 14556 -s HIGHRES_IMU -r 20
@@ -20,6 +20,6 @@ mavlink stream -u 14556 -s MANUAL_CONTROL -r 10
 
 
 navio_sysfs_rc_in start
-navio_sysfs_pwm_out start
+navio_sysfs_pwm_out start -m ROMFS/px4fmu_common/mixers/AERT.main.mix
 logger start -t
 mavlink boot_complete