usb: dwc3-generic: Add the size of regs property to glue structure

Add the size of regs property to the glue structure to correctly
specify the register region to map.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/dwc3/dwc3-generic.h b/drivers/usb/dwc3/dwc3-generic.h
index 824f678..40902c8 100644
--- a/drivers/usb/dwc3/dwc3-generic.h
+++ b/drivers/usb/dwc3/dwc3-generic.h
@@ -17,6 +17,7 @@
 	struct clk_bulk		clks;
 	struct reset_ctl_bulk	resets;
 	fdt_addr_t regs;
+	fdt_size_t size;
 };
 
 struct dwc3_glue_ops {