usb: gadget: sdp: use CONFIG_SDP_LOADADDR as default load address

If SDP_WRITE and SDP_JUMP addr is zero, use CONFIG_SDP_LOADADDR
as default address

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 58ca82d..46aa3fe 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -122,6 +122,10 @@
 	   This value will be used except for system-specific gadget
 	   drivers that have more specific information.
 
+config SDP_LOADADDR
+	hex "Default load address at SDP_WRITE and SDP_JUMP"
+	default 0
+
 # Selected by UDC drivers that support high-speed operation.
 config USB_GADGET_DUALSPEED
 	bool