MAINTAINERS: update email address for Felix Fietkau

The old address has been bouncing for a while now
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: David S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -10808,7 +10808,7 @@ F:	Documentation/devicetree/bindings/dma/mtk-*
 F:	drivers/dma/mediatek/
 
 MEDIATEK ETHERNET DRIVER
-M:	Felix Fietkau <nbd@openwrt.org>
+M:	Felix Fietkau <nbd@nbd.name>
 M:	John Crispin <john@phrozen.org>
 M:	Sean Wang <sean.wang@mediatek.com>
 M:	Mark Lee <Mark-MC.Lee@mediatek.com>