Only read pan ID when address mode is not 0, when reading 802.15.4 header
make: remove dependency from flash to all

* print message when no hex file is found instead
* add objcopy for native so that flash can succeed
Merge pull request #1724 from LudwigOrtmann/flash-all

make: remove dependency from flash to all
Merge pull request #1802 from Troels51/ieee-802.15.4-frame-format-fix

fix in ieee 802.15.4 frame