defconfig: 8610: Increase default Kmemleak log size to 4000 from 400

The intention of this change is to help with memory leak
debugging, without any need to change the config file

Change-Id: Iba588e9efe4d7c67c66de75684f4539e3b532a3c
Signed-off-by: Sunil Kumar Devalokam Murali <sdevalok@codeaurora.org>