selftests: net: Adding config fragment CONFIG_NUMA=y

kernel config fragement CONFIG_NUMA=y is need for reuseport_bpf_numa.
Signed-off-by: NNaresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tools/testing/selftests/net/config

 CONFIG_USER_NS=y
 CONFIG_BPF_SYSCALL=y
 CONFIG_TEST_BPF=m
+CONFIG_NUMA=y