cmake HAVE_NETPACKET_PACKET_H examples

CTSRD-CHERI/cheribsd contrib/libpcap/CMakeLists.txt :662 

check_include_file(netpacket/packet.h HAVE_NETPACKET_PACKET_H)

asset-group/5ghoul-5g-nr-attacks libs/libpcap/CMakeLists.txt :386 

check_include_file(netpacket/packet.h HAVE_NETPACKET_PACKET_H)