MAINTAINERS: add devicetree bindings entry for mt76

Specify devicetree bindings entry for mt76 driver.
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/8cbfeceef642ede408b4922c363953cb243cd87f.1646766851.git.lorenzo@kernel.org

MAINTAINERS

@@ -12149,6 +12149,7 @@ R:	Shayne Chen <shayne.chen@mediatek.com>
 R:	Sean Wang <sean.wang@mediatek.com>
 L:	linux-wireless@vger.kernel.org
 S:	Maintained
+F:	Documentation/devicetree/bindings/net/wireless/mediatek,mt76.yaml
 F:	drivers/net/wireless/mediatek/mt76/
 
 MEDIATEK MT7601U WIRELESS LAN DRIVER