defconfig: msm: Enable cnss_genl driver for sa6155

cnss_genl driver creates a netlink family and multicast groups
to facilitate communication between WLAN driver and userspace.
Define flag CONFIG_CNSS_GENL and set to 'y'(yes) to enable
compilation of the cnss_genl driver inorder to use the same.

Change-Id: I8c0c34fdcc6ae67f3c1e9028c8e4840e87b6105c
CRs-Fixed: 2413994
Signed-off-by: Sandeep Singh <sandsing@codeaurora.org>
Signed-off-by: Min Liu <minliu@codeaurora.org>