phy: mediatek: add MediaTek T-PHY support for PCIe

The driver provides PHY for USB2, USB3.0, PCIe and SATA, and now
we just enable PCIe. As for the other functionalities will be
added gradually in upcoming days.

This is adapted from the Linux version.

Tested-by: Frank Wunderlich <frank-w@public-files.de>
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 0231227..e317373 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -205,4 +205,15 @@
 
 	  This PHY is found on MT76x8 devices supporting USB.
 
+config PHY_MTK_TPHY
+	bool "MediaTek T-PHY Driver"
+	depends on PHY
+	depends on ARCH_MEDIATEK
+	help
+	  MediaTek T-PHY driver supports usb2.0, usb3.0 ports, PCIe and
+	  SATA, and meanwhile supports two version T-PHY which have
+	  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.
+
 endmenu