MAINTAINERS: eth: mvneta: update entry

Add myself as driver maintainer and restore the maintained status.
While at it, update the file field to cover mvneta_bm part of the driver.
Signed-off-by: Marcin Wojtas <marcin.s.wojtas@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -12869,9 +12869,10 @@ S:	Maintained
 F:	drivers/thermal/armada_thermal.c
 
 MARVELL MVNETA ETHERNET DRIVER
+M:	Marcin Wojtas <marcin.s.wojtas@gmail.com>
 L:	netdev@vger.kernel.org
-S:	Orphan
-F:	drivers/net/ethernet/marvell/mvneta.*
+S:	Maintained
+F:	drivers/net/ethernet/marvell/mvneta*
 
 MARVELL MVPP2 ETHERNET DRIVER
 M:	Marcin Wojtas <marcin.s.wojtas@gmail.com>