MAINTAINERS: Change Maintainer for CAIF

Dmitry Tarnyagin will take over as maintainer for CAIF.

Cc: Dmitry Tarnyagin <dmitry.tarnyagin@stericsson.com>
Cc: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>