POSIX: Added missing include path and -Wno-packed flag
POSIX: Added missing include path and -Wno-packed flag

The changes to the simulator added an include of

mavlink/include/v1.0/... to simulator.h which was not in the included paths.

The included header file also causes clang to issue a -Wpacked warning that
had to be silenced.

Signed-off-by: Mark Charlebois <f1891e7fc976ae1bd489627e2954fb730751d728@gmail.com>

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