MAINTAINERS: net: add entry for Freescale QorIQ DPAA Ethernet driver

Add record for Freescale QORIQ DPAA Ethernet driver adding myself as
maintainer.

Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>