cmake HAVE_NET_IF_TYPES_H examples

CTSRD-CHERI/cheribsd contrib/libpcap/CMakeLists.txt :2125 

check_include_files("net/if.h;net/if_dl.h;net/if_types.h" HAVE_NET_IF_TYPES_H)

asset-group/5ghoul-5g-nr-attacks libs/libpcap/CMakeLists.txt :1364 

check_include_files("net/if.h;net/if_dl.h;net/if_types.h"
                        HAVE_NET_IF_TYPES_H)