platform: sifive/fu540: Fix up DT for reserved memory

This calls fdt_reserved_memory_fixup() helper in the platform's
final_init() routine.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

platform/sifive/fu540/platform.c

@@ -89,6 +89,8 @@ static void fu540_modify_dt(void *fdt)
 			   "/soc/serial@10010000:115200");
 
 	fdt_plic_fixup(fdt, "riscv,plic0");
+
+	fdt_reserved_memory_fixup(fdt);
 }
 
 static int fu540_final_init(bool cold_boot)