ast2500: defconfig: Add USB gadget

The USB gadget is needed to implement Virtual Media.

This adds about 46kB to the kernel image:
Before:
-rw-r--r-- 2 anoo anoo  2542904 Jan 19 14:53 fitImage--4.19.16+git0+bbc22aa295-r0-witherspoon-20190119205057.bin
After:
-rw-r--r-- 2 anoo anoo  2589648 Jan 18 10:20 fitImage--4.19.16+git0+bbc22aa295-r0-witherspoon-20190118155445.bin

Change-Id: I688e8734f6d8e0fa612785204630870d824cb46f
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/recipes-kernel/linux/ast2500/defconfig b/recipes-kernel/linux/ast2500/defconfig
index 9673241..2869a64 100755
--- a/recipes-kernel/linux/ast2500/defconfig
+++ b/recipes-kernel/linux/ast2500/defconfig
@@ -189,6 +189,10 @@
 CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_EHCI_ROOT_HUB_TT=y
 CONFIG_USB_EHCI_HCD_PLATFORM=y
+CONFIG_USB_GADGET=y
+CONFIG_USB_ASPEED_VHUB=y
+CONFIG_USB_CONFIGFS=y
+CONFIG_USB_CONFIGFS_MASS_STORAGE=y
 CONFIG_NEW_LEDS=y
 CONFIG_LEDS_CLASS=y
 CONFIG_LEDS_CLASS_FLASH=y