defconfig: arm64: sdm845: Enable IP6_NF_IPTABLES_128

This enables 128 bit matching in ip6tables to help
optimize cases where there is no match required.
This shows a rough improvement of 40Mbps in a UDPv6
downlink test using iperf.

CRs-Fixed: 2122802
Change-Id: I0c43f6cd1ba6016a145a351208d453f999727602
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>