Commit 2036ae4 (base-files: support hostname and ntp servers through board.d)
was supposed to implement these procedures but lacked the required changes
to uci-defaults.sh.
Add the missing procedures now to fix config generation on targets relying
on hostname or NTP server presetting.
Fixes FS#754.
Reported-by: Cristian Morales Vega <cristian@samknows.com>
Signed-off-by: Jo-Philipp Wich <jo@mein.io>