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/configs/cm_t35_defconfig b/configs/cm_t35_defconfig
index cfb68b1..0cb6e72 100644
--- a/configs/cm_t35_defconfig
+++ b/configs/cm_t35_defconfig
@@ -52,6 +52,7 @@
 CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_MUSB_UDC=y
 CONFIG_USB_OMAP3=y
+CONFIG_TWL4030_USB=y
 CONFIG_USB_STORAGE=y
 CONFIG_LCD=y
 CONFIG_OF_LIBFDT=y