Convert CONFIG_USB_GADGET_DWC2_OTG_PHY to Kconfig

This converts the following to Kconfig:
   CONFIG_USB_GADGET_DWC2_OTG_PHY

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/trats2_defconfig b/configs/trats2_defconfig
index 5c47a22..b48ed9c 100644
--- a/configs/trats2_defconfig
+++ b/configs/trats2_defconfig
@@ -62,6 +62,7 @@
 CONFIG_USB_GADGET_VENDOR_NUM=0x04e8
 CONFIG_USB_GADGET_PRODUCT_NUM=0x6601
 CONFIG_USB_GADGET_DWC2_OTG=y
+CONFIG_USB_GADGET_DWC2_OTG_PHY=y
 CONFIG_USB_GADGET_DOWNLOAD=y
 CONFIG_USB_FUNCTION_THOR=y
 CONFIG_LIB_HW_RAND=y