ARM64: zynqmp: Define config USB_STORAGE through defconfig

Define config USB_STORAGE through defconfig for all
Xilinx ZynqMP boards.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/xilinx_zynqmp_ep_defconfig b/configs/xilinx_zynqmp_ep_defconfig
index b6dee51..f702381 100644
--- a/configs/xilinx_zynqmp_ep_defconfig
+++ b/configs/xilinx_zynqmp_ep_defconfig
@@ -65,6 +65,7 @@
 CONFIG_USB_XHCI_DWC3=y
 CONFIG_USB_DWC3=y
 CONFIG_USB_DWC3_GADGET=y
+CONFIG_USB_STORAGE=y
 CONFIG_USB_GADGET=y
 CONFIG_USB_GADGET_DOWNLOAD=y
 CONFIG_G_DNL_MANUFACTURER="Xilinx"