MAINTAINERS: add USB driver to ARM MEDIATEK

Add MediaTek USB3 Dual-Role controller driver to ARM MEDIATEK,
and add myself as a maintainer for it.

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index fb9ba37..5047ec6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -266,6 +266,7 @@
 ARM MEDIATEK
 M:	Ryder Lee <ryder.lee@mediatek.com>
 M:	Weijie Gao <weijie.gao@mediatek.com>
+M:	Chunfeng Yun <chunfeng.yun@mediatek.com>
 R:	GSS_MTK_Uboot_upstream <GSS_MTK_Uboot_upstream@mediatek.com>
 S:	Maintained
 F:	arch/arm/mach-mediatek/
@@ -282,6 +283,8 @@
 F:	drivers/ram/mediatek/
 F:	drivers/spi/mtk_snfi_spi.c
 F:	drivers/timer/mtk_timer.c
+F:	drivers/usb/host/xhci-mtk.c
+F:	drivers/usb/mtu3/
 F:	drivers/watchdog/mtk_wdt.c
 F:	drivers/net/mtk_eth.c
 F:	drivers/reset/reset-mediatek.c