net: update macro for SOCKEV netlink proto

Due to conflict of same protocol value used by SOCKEV and rmnet_data,
rmnet_data was not able to setup its netlink messaging framework.
Fix make SOCKEV to use different value to avoid conflict.

Change-Id: I06a5872ddb43730e25343dcc0776f4b7240ed1fb
Signed-off-by: Kaustubh Pandey <kapandey@codeaurora.org>