powerpc/kernel: Use of_property_read_u32() in rtas_initialize()

This uses of_property_read_u32() in rtas_initialize() so that we
needn't explicitly care the CPU's endian.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/rtas.c

@@ -1145,7 +1145,8 @@ asmlinkage int ppc_rtas(struct rtas_args __user *uargs)
 void __init rtas_initialize(void)
 {
 	unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
-	const __be32 *basep, *entryp, *sizep;
+	u32 base, size, entry;
+	int no_base, no_size, no_entry;
 
 	/* Get RTAS dev node and fill up our "rtas" structure with infos
 	 * about it.
@@ -1154,20 +1155,17 @@ void __init rtas_initialize(void)
 	if (!rtas.dev)
 		return;
 
-	basep = of_get_property(rtas.dev, "linux,rtas-base", NULL);
-	sizep = of_get_property(rtas.dev, "rtas-size", NULL);
-	if (basep == NULL || sizep == NULL) {
+	no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base);
+	no_size = of_property_read_u32(rtas.dev, "rtas-size", &size);
+	if (no_base || no_size) {
 		rtas.dev = NULL;
 		return;
 	}
 
-	rtas.base = __be32_to_cpu(*basep);
-	rtas.size = __be32_to_cpu(*sizep);
-	entryp = of_get_property(rtas.dev, "linux,rtas-entry", NULL);
-	if (entryp == NULL) /* Ugh */
-		rtas.entry = rtas.base;
-	else
-		rtas.entry = __be32_to_cpu(*entryp);
+	rtas.base = base;
+	rtas.size = size;
+	no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry);
+	rtas.entry = no_entry ? rtas.base : entry;
 
 	/* If RTAS was found, allocate the RMO buffer for it and look for
 	 * the stop-self token if any