add AF_XDP to sys/socket.h from linux v4.18
treed963badc38b9bd7976258ffc92a20e22a8794a1e
-rw-r--r-- 61 .gitignore
-rw-r--r-- 5859 COPYRIGHT
-rw-r--r-- 6467 INSTALL
-rw-r--r-- 7373 Makefile
-rw-r--r-- 1028 README
-rw-r--r-- 7 VERSION
-rw-r--r-- 76232 WHATSNEW
drwxr-xr-x - arch
-rwxr-xr-x 23264 configure
drwxr-xr-x - crt
drwxr-xr-x - dist
-rw-r--r-- 411 dynamic.list
drwxr-xr-x - include
drwxr-xr-x - ldso
drwxr-xr-x - src
drwxr-xr-x - tools