Partially revert "net: socket: implement 64-bit timestamps"

Partially revert "net: socket: implement 64-bit timestamps"

The introduction of SIOCGSTAMP{,NS}_OLD and move of SICOGSTAMP{,NS} to
a different header has caused build failures for various user-space
programs including qemu and suricata.  It also causes a test failure
for glibc.

For now, remove the _OLD suffix on the old ioctl numbers and require
programs using 64-bit timestamps to explicitly use SIOCGSTAMP{,NS}_NEW.

References: https://lore.kernel.org/lkml/af0eb47a-5b98-1bd9-3e8d-652e7f28b01f@de.ibm.com/
References: https://bugs.debian.org/934316
References: https://ci.debian.net/data/autopkgtest/testing/amd64/g/glibc/2772289/log.gz
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Gbp-Pq: Topic bugfix/all
Gbp-Pq: Name partially-revert-net-socket-implement-64-bit-timestamps.patch