ARM: versatile: fix OF node leak in CPUs prepare

Machine code is leaking OF node reference from of_find_matching_node()
in realview_smp_prepare_cpus().

Fixes: 5420b4b15617 ("ARM: realview: add an DT SMP boot method")
Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Acked-by: Liviu Dudau <[e-mail]>
Link: https://lore.kernel.org/[e-mail]
Signed-off-by: Linus Walleij <[e-mail]>

arch/arm/mach-versatile/platsmp-realview.c

···
 		return;
 	}
 	map = syscon_node_to_regmap(np);
+	of_node_put(np);
 	if (IS_ERR(map)) {
 		pr_err("PLATSMP: No syscon regmap\n");
 		return;