compat.h: Add more address family symbols for older glibc.

This patch fixes these build errors with glibc before 2.10.

syscalls/socket.c:27: error: ‘AF_CAN’ undeclared here (not in a function)
syscalls/socket.c:33: error: ‘AF_LLC’ undeclared here (not in a function)
syscalls/socket.c:38: error: ‘AF_PHONET’ undeclared here (not in a function)
syscalls/socket.c:39: error: ‘AF_RDS’ undeclared here (not in a function)
syscalls/socket.c:40: error: ‘AF_TIPC’ undeclared here (not in a function)

Signed-off-by: Vinson Lee <vlee@twitter.com>