MAINTAINERS: net: netsec: add myself as co-maintainer

Add myself as co-maintainer for Socionext netsec driver.
This commit also removes Jassi from maintainer since he
no longer has a Developerbox.

Cc: Jassi Brar <jaswinder.singh@linaro.org>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Masahisa Kojima <kojima.masahisa@socionext.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>