rockchip: roc-rk3399-pc: Enable USB Gadget

Enable DWC3 core, gadget for roc-rk3399-pc board.

This would help to use fastboot by default.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/configs/roc-pc-mezzanine-rk3399_defconfig b/configs/roc-pc-mezzanine-rk3399_defconfig
index b3c8f19..b2c370c 100644
--- a/configs/roc-pc-mezzanine-rk3399_defconfig
+++ b/configs/roc-pc-mezzanine-rk3399_defconfig
@@ -13,6 +13,7 @@
 CONFIG_SPL_SPI_FLASH_SUPPORT=y
 CONFIG_SPL_SPI_SUPPORT=y
 CONFIG_DEBUG_UART=y
+# CONFIG_ANDROID_BOOT_IMAGE is not set
 CONFIG_DEFAULT_FDT_FILE="rockchip/rk3399-roc-pc-mezzanine.dtb"
 CONFIG_DISPLAY_BOARDINFO_LATE=y
 # CONFIG_SPL_RAW_IMAGE_SUPPORT is not set
@@ -65,7 +66,9 @@
 CONFIG_USB_EHCI_GENERIC=y
 CONFIG_USB_DWC3=y
 CONFIG_USB_DWC3_GENERIC=y
+CONFIG_ROCKCHIP_USB2_PHY=y
 CONFIG_USB_KEYBOARD=y
+CONFIG_USB_GADGET=y
 CONFIG_USB_HOST_ETHER=y
 CONFIG_USB_ETHER_ASIX=y
 CONFIG_USB_ETHER_ASIX88179=y