support: Add support_socket_so_timestamp_time64

Check if the socket support 64-bit network packages timestamps
(SO_TIMESTAMP and SO_TIMESTAMPNS).  This will be used on recvmsg
and recvmmsg tests to check if the timestamp should be generated.

Reviewed-by: Florian Weimer <fweimer@redhat.com>

(cherry picked from 38bc0f4e)