drivers/of: Constify device_node->name and ->path_component_name

Neither of these should ever be changed once set. Make them const and
fix up the users that try to modify it in-place. In one case
kmalloc+memcpy is replaced with kstrdup() to avoid modifying the string.

Build tested with defconfigs on ARM, PowerPC, Sparc, MIPS, x86 among
others.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Julian Calaby <julian.calaby@gmail.com>
diff --git a/arch/sparc/kernel/pci_impl.h b/arch/sparc/kernel/pci_impl.h
index 918a203..5f68853 100644
--- a/arch/sparc/kernel/pci_impl.h
+++ b/arch/sparc/kernel/pci_impl.h
@@ -88,7 +88,7 @@
 	int				chip_revision;
 
 	/* Name used for top-level resources. */
-	char				*name;
+	const char			*name;
 
 	/* OBP specific information. */
 	struct platform_device		*op;