cpufreq: ap806: fix possible object reference leak

The call to of_find_compatible_node returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.

Detected by coccinelle with the following warnings:
./drivers/cpufreq/armada-8k-cpufreq.c:187:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 130, but without a corresponding object release within this function.
./drivers/cpufreq/armada-8k-cpufreq.c:191:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 130, but without a corresponding object release within this function.

Signed-off-by: Wen Yang <[e-mail]>
Cc: Jason Cooper <[e-mail]>
Cc: Andrew Lunn <[e-mail]>
Cc: Gregory Clement <[e-mail]>
Cc: Sebastian Hesselbarth <[e-mail]>
Cc: "Rafael J. Wysocki" <[e-mail]>
Cc: Viresh Kumar <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Viresh Kumar <[e-mail]>

drivers/cpufreq/armada-8k-cpufreq.c

···
 		of_node_put(node);
 		return -ENODEV;
 	}
+	of_node_put(node);
 
 	nb_cpus = num_possible_cpus();
 	freq_tables = kcalloc(nb_cpus, sizeof(*freq_tables), GFP_KERNEL);