This commit adds a new configuration option, `dst_addr` to the
'sntp_client' that accepts either an IP address or a DNS hostname. If a
DNS hostname is provided, the 'sntp_client' will resolve the IP address
before each SNTP request. The 'dst_ip' configuration option is
deprecated but kept for compatibility until 'dst_addr' is fully adopted.
xsd/net_types.xsd: add Net_address type
sntp_dummy_rtc: adjust configuration to use pool.ntp.org
Fixesgenodelabs/genode#5003
This recipe combines the dummy_rtc_drv, which consumes a given time,
and provides the "Rtc" service to its clients with the simple NTP client,
which provides the current time to the RTC driver in regular intervals.
Ref genodelabs/genode#4687
