phy: phy-mt65xx-usb3: add mediatek directory and rename file

The driver is actually for T-PHY which supports USB3.0, PCIe and SATA,
and supports more SoCs now, but not just only for series of mt65xx SoCs,
so the name of file, data struct, functions etc with 'mt65xx' may cause
misunderstanding when new SoCs are supported. Here rename them to reflect
the real functions and also enhance readability.

And also update MAINTAINERS file to reflect the correct driver

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/mediatek/Kconfig

@@ -0,0 +1,14 @@
+#
+# Phy drivers for Mediatek devices
+#
+config PHY_MTK_TPHY
+    tristate "MediaTek T-PHY Driver"
+    depends on ARCH_MEDIATEK && OF
+    select GENERIC_PHY
+    help
+      Say 'Y' here to add support for MediaTek T-PHY driver,
+      it supports multiple 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.

drivers/phy/mediatek/Makefile

@@ -0,0 +1,5 @@
+#
+# Makefile for the phy drivers.
+#
+
+obj-$(CONFIG_PHY_MTK_TPHY)		+= phy-mtk-tphy.o