posix-configs: start HMC5883 before MPU9250 in DF
posix-configs: start HMC5883 before MPU9250 in DF

We need to start the external mag before we start the internal mag on
the MPU9250 because the ekf2 does not support voting for the sensor with
the highest priority (or failures) yet, so it will just subscribe to
whatever is at 0.

mcgill-robotics/Firmware,krbeverx/Firmware,mje-nz/PX4-Firmware,mcgill-robotics/Firmware,PX4/Firmware,Aerotenna/Firmware,dagar/Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,mcgill-robotics/Firmware,dagar/Firmware,mje-nz/PX4-Firmware,dagar/Firmware,mcgill-robotics/Firmware,dagar/Firmware,Aerotenna/Firmware,krbeverx/Firmware,Aerotenna/Firmware,dagar/Firmware,mcgill-robotics/Firmware,darknight-007/Firmware,Aerotenna/Firmware,PX4/Firmware,mje-nz/PX4-Firmware,darknight-007/Firmware,mcgill-robotics/Firmware,Aerotenna/Firmware,jlecoeur/Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,krbeverx/Firmware,PX4/Firmware,krbeverx/Firmware,jlecoeur/Firmware,acfloria/Firmware,mje-nz/PX4-Firmware,PX4/Firmware,mcgill-robotics/Firmware,darknight-007/Firmware,acfloria/Firmware,dagar/Firmware,darknight-007/Firmware,jlecoeur/Firmware,acfloria/Firmware,Aerotenna/Firmware,acfloria/Firmware,jlecoeur/Firmware,acfloria/Firmware,mje-nz/PX4-Firmware,PX4/Firmware,Aerotenna/Firmware,PX4/Firmware,jlecoeur/Firmware,acfloria/Firmware,jlecoeur/Firmware,acfloria/Firmware,PX4/Firmware,darknight-007/Firmware,krbeverx/Firmware,jlecoeur/Firmware,jlecoeur/Firmware,dagar/Firmware