MAINTAINERS: Drop inactive Vitaly Bordug's email

The Vitaly Bordug's email bounces ("ru.mvista.com: Name or service not
known") and there was no activity (ack, review, sign) since 2009.

Cc: Vitaly Bordug <vitb@kernel.crashing.org>
Cc: Pantelis Antoniou <pantelis.antoniou@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>