[qca-nss-ecm] ifdef'd all the IPIP6 interface code.

* This will make it easy to remove IPIP6 code from the compilation.

Change-Id: Ic6981bbfabde1551dde8814277d9d4491a55b710
Signed-off-by: Murat Sezgin <msezgin@codeaurora.org>
5 files changed