MAINTAINERS: Remove myself as co-maintainer for qcom-ethqos

As I am no longer with Linaro, I no longer have access to documentation
for this IP. The Linaro email will start bouncing soon.

Vinod is fully capable to maintain this driver by himself, therefore
remove myself as co-maintainer for qcom-ethqos.

Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>