usb: xhci-mtk: add support for MediaTek MT7621 SoC

This patch makes xhci-mtk driver available for MediaTek MT7621 SoC

Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index 31ae9f7..c3b97f4 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -42,7 +42,7 @@
 
 config USB_XHCI_MTK
 	bool "Support for MediaTek on-chip xHCI USB controller"
-	depends on ARCH_MEDIATEK
+	depends on ARCH_MEDIATEK || SOC_MT7621
 	help
 	  Enables support for the on-chip xHCI controller on MediaTek SoCs.