MAINTAINERS: update Lorenzo's email address

Using my kernel.org email.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/e98fcf759f8c23a9736f1c4d20ca0437e4b145de.1648120046.git.lorenzo@kernel.org

MAINTAINERS

@@ -12222,7 +12222,7 @@ F:	drivers/mmc/host/mtk-sd.c
 MEDIATEK MT76 WIRELESS LAN DRIVER
 M:	Felix Fietkau <nbd@nbd.name>
-M:	Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
+M:	Lorenzo Bianconi <lorenzo@kernel.org>
 M:	Ryder Lee <ryder.lee@mediatek.com>
 R:	Shayne Chen <shayne.chen@mediatek.com>
 R:	Sean Wang <sean.wang@mediatek.com>