hw/riscv: use ms->fdt in riscv_socket_fdt_write_distance_matrix()

There's no need to use a MachineState pointer and a fdt pointer now that
all RISC-V machines are using the FDT from the MachineState.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230111170948.316276-7-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

hw/riscv/spike.c

@@ -174,7 +174,7 @@ static void create_fdt(SpikeState *s, const MemMapEntry *memmap,
         g_free(clust_name);
     }
 
-    riscv_socket_fdt_write_distance_matrix(mc, fdt);
+    riscv_socket_fdt_write_distance_matrix(mc);
 
     qemu_fdt_add_subnode(fdt, "/chosen");
     qemu_fdt_setprop_string(fdt, "/chosen", "stdout-path", "/htif");