of: put default string compare and #a/s-cell values into common header

Most architectures don't need to change these.  Put them into common
code to eliminate some duplication

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Michal Simek <monstr@monstr.eu>
diff --git a/include/linux/of.h b/include/linux/of.h
index 48b0ee6..5cd2840 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -116,6 +116,19 @@
 
 #include <asm/prom.h>
 
+/* Default #address and #size cells.  Allow arch asm/prom.h to override */
+#if !defined(OF_ROOT_NODE_ADDR_CELLS_DEFAULT)
+#define OF_ROOT_NODE_ADDR_CELLS_DEFAULT 1
+#define OF_ROOT_NODE_SIZE_CELLS_DEFAULT 1
+#endif
+
+/* Default string compare functions, Allow arch asm/prom.h to override */
+#if !defined(of_compat_cmp)
+#define of_compat_cmp(s1, s2, l)	strncasecmp((s1), (s2), (l))
+#define of_prop_cmp(s1, s2)		strcmp((s1), (s2))
+#define of_node_cmp(s1, s2)		strcasecmp((s1), (s2))
+#endif
+
 /* flag descriptions */
 #define OF_DYNAMIC	1 /* node and properties were allocated via kmalloc */
 #define OF_DETACHED	2 /* node has been detached from the device tree */