Instead of changing POKY_DEFAULT_DISTRO_FEATURES, do the distro features
configuration directly in the DISTRO_FEATURES variable. Also, add a couple
of variables (MACHINE_DISTRO_FEATURES_ADD/REMOVE) that allow machines
for extra tweaking the distro features.
While on it, clean up some distro features:
- pulseaudio: already added by DISTRO_FEATURES_BACKFILL
- bluez5, splashscreen, initrd, gplv3: not used (dead code)
Signed-off-by: Javier Viguera <javier.viguera@digi.com>
c01c394806