px4fmu-v2_default: save more flash
px4fmu-v2_default: save more flash

This disables the following modules to save flash:
- mpu9250 driver because the MPU9250 is rarely used on Pixhawks
- Snapdragon RC PWM passthrough which is rarely used and definitely a
  special/custom configuration. Also, it will soon be obsolete with the
  upcoming PWM support on Snapdragon.

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