nios2: get cpu node with of_get_cpu_node

"device_type" use is deprecated for FDT though it has continued to be used
for nodes like cpu nodes. Use of_get_cpu_node() instead which works using
node names by default. This will allow the eventually removal of cpu
device_type properties.

Also, fix a leaked reference by adding a missing of_node_put.

Cc: Ley Foon Tan <[e-mail]>
Cc: [e-mail]
Signed-off-by: Rob Herring <[e-mail]>

arch/nios2/kernel/cpuinfo.c

···
 	const char *str;
 	int len;
 
-	cpu = of_find_node_by_type(NULL, "cpu");
+	cpu = of_get_cpu_node(0, NULL);
 	if (!cpu)
 		panic("%s: No CPU found in devicetree!\n", __func__);
 
···
 	cpuinfo.reset_addr = fcpu(cpu, "altr,reset-addr");
 	cpuinfo.exception_addr = fcpu(cpu, "altr,exception-addr");
 	cpuinfo.fast_tlb_miss_exc_addr = fcpu(cpu, "altr,fast-tlb-miss-addr");
+
+	of_node_put(cpu);
 }
 
 #ifdef CONFIG_PROC_FS