Convert CONFIG_TWL4030_USB to Kconfig

This converts the following to Kconfig:
   CONFIG_TWL4030_USB

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
new file mode 100644
index 0000000..943a966
--- /dev/null
+++ b/drivers/usb/phy/Kconfig
@@ -0,0 +1,12 @@
+#
+# (C) Copyright 2017
+# Adam Ford, Logic PD, aford173@gmail.com
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+comment "USB Phy"
+
+config TWL4030_USB
+	bool "TWL4030 PHY"
+