phy: mediatek: add XS-PHY driver

Support XS-PHY for MediaTek SoCs with USB3.1 GEN2 controller
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/mediatek/Kconfig

@@ -12,3 +12,12 @@ config PHY_MTK_TPHY
 	  different banks layout, the T-PHY with shared banks between
 	  multi-ports is first version, otherwise is second veriosn,
 	  so you can easily distinguish them by banks layout.
+
+config PHY_MTK_XSPHY
+    tristate "MediaTek XS-PHY Driver"
+    depends on ARCH_MEDIATEK && OF
+    select GENERIC_PHY
+    help
+	  Enable this to support the SuperSpeedPlus XS-PHY transceiver for
+	  USB3.1 GEN2 controllers on MediaTek chips. The driver supports
+	  multiple USB2.0, USB3.1 GEN2 ports.

drivers/phy/mediatek/Makefile

@@ -3,3 +3,4 @@
 #
 
 obj-$(CONFIG_PHY_MTK_TPHY)		+= phy-mtk-tphy.o
+obj-$(CONFIG_PHY_MTK_XSPHY)		+= phy-mtk-xsphy.o