riscv: sifive_u: Fix clock-names property for ethernet node

The correct property name is clock-names, not clocks-names.

Without this patch, the Ethernet driver fails to instantiate with
the following error.

macb 100900fc.ethernet: failed to get macb_clk (-2)
macb: probe of 100900fc.ethernet failed with error -2

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

hw/riscv/sifive_u.c

@@ -215,7 +215,7 @@ static void *create_fdt(SiFiveUState *s, const struct MemmapEntry *memmap,
     qemu_fdt_setprop_cells(fdt, nodename, "interrupts", SIFIVE_U_GEM_IRQ);
     qemu_fdt_setprop_cells(fdt, nodename, "clocks",
         ethclk_phandle, ethclk_phandle, ethclk_phandle);
-    qemu_fdt_setprop(fdt, nodename, "clocks-names", ethclk_names,
+    qemu_fdt_setprop(fdt, nodename, "clock-names", ethclk_names,
         sizeof(ethclk_names));
     qemu_fdt_setprop_cells(fdt, nodename, "#address-cells", 1);
     qemu_fdt_setprop_cells(fdt, nodename, "#size-cells", 0);