Revert "Revert "defconfig: mdm9615: enable iptables configs""

This reverts commit da4f8b7f.

The original change caused the ar6000.ko driver to grow in size
by about 2MB. This caused the rootfs to run out of space and
therefore we had to revert the change. We have now moved the
dlkm's into /usr instead of /lib/modules and thereby we can
re-enable the iptables configs.

Change-Id: Id5d34fe563115de46432a433c62b3bf0a4e91be0
Signed-off-by: Shruthi Krishna <skrish@codeaurora.org>
Signed-off-by: Sridhar Parasuram <sridhar@codeaurora.org>