phy: ralink-usb: add driver for Mediatek/Ralink

Add a driver to setup the USB phy on Mediatek/Ralink SoCs.
The driver sets up power and host mode, but also needs to
configure PHY registers for the MT7628 and MT7688.

Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
diff --git a/drivers/phy/ralink/Kconfig b/drivers/phy/ralink/Kconfig
new file mode 100644
index 0000000..b17635b
--- /dev/null
+++ b/drivers/phy/ralink/Kconfig
@@ -0,0 +1,11 @@
+#
+# PHY drivers for Ralink platforms.
+#
+config PHY_RALINK_USB
+	tristate "Ralink USB PHY driver"
+	depends on RALINK || COMPILE_TEST
+	select GENERIC_PHY
+	select MFD_SYSCON
+	help
+	  This option enables support for the Ralink USB PHY found inside
+	  RT3352, MT7620, MT7628 and MT7688.