defconfig: sdm670: Enable INET_UDP_DIAG

Enable config to enable UDP stats collection by ss tool.
  "ss -uneiopan" should work now.

Change-Id: I6535055c12646826e6f96e8cb17dc8bf5e02f37e
Signed-off-by: Tejaswi Tanikella <tejaswit@codeaurora.org>