bpf: only build sockmap with CONFIG_INET

The sockmap infrastructure is only aware of TCP sockets at the
moment. In the future we plan to add UDP. In both cases CONFIG_NET
should be built-in.

So lets only build sockmap if CONFIG_INET is enabled.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

kernel/bpf/Makefile

@@ -9,9 +9,11 @@ obj-$(CONFIG_BPF_SYSCALL) += devmap.o
 obj-$(CONFIG_BPF_SYSCALL) += cpumap.o
 obj-$(CONFIG_BPF_SYSCALL) += offload.o
 ifeq ($(CONFIG_STREAM_PARSER),y)
+ifeq ($(CONFIG_INET),y)
 obj-$(CONFIG_BPF_SYSCALL) += sockmap.o
 endif
 endif
+endif
 ifeq ($(CONFIG_PERF_EVENTS),y)
 obj-$(CONFIG_BPF_SYSCALL) += stackmap.o
 endif