* Remove DT_FROM_BD_ENABLE. We don't have anything particular in BD.
* Adding pl-conf.dtsi in system-top otherwise is gets lost and unused.

* This parse a configuration file and then load the FPGA with the
  correct bitstream (centralnode or cellnode)

Struggling with petalinux update: it is no longer possible to log as
root without the tweaks.

From user diag, it is possible to sudo.

* Use their headless recipe
* overlay external_hdf, add one xsa (central node)
* Include PyTango in image