of: Only compile OF_DYNAMIC on PowerPC pseries and iseries

Only two architectures use the OF node reference counting and reclaim bits.
There is no need to compile it for the rest of the PowerPC platforms or for
any of the other architectures.  This patch makes iseries and pseries
select CONFIG_OF_DYNAMIC, and makes it default to off for everything else.

It is still safe to turn on CONFIG_OF_DYNAMIC on all architectures, it just
isn't necessary.

v2: Also select OF_DYNAMIC for PPC_CHROMA and MPC885ADS as reported by Michael
    Meuling

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Jimi Xenidis <jimix@pobox.com> (for PPC_CHROMA bug fix)
Cc: Rob Herring <rob.herring@calxeda.com>
diff --git a/include/linux/of.h b/include/linux/of.h
index 5a4a3ad..533603e 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -72,19 +72,17 @@
 	uint32_t args[MAX_PHANDLE_ARGS];
 };
 
-#if defined(CONFIG_SPARC) || !defined(CONFIG_OF)
+#ifdef CONFIG_OF_DYNAMIC
+extern struct device_node *of_node_get(struct device_node *node);
+extern void of_node_put(struct device_node *node);
+#else /* CONFIG_OF_DYNAMIC */
 /* Dummy ref counting routines - to be implemented later */
 static inline struct device_node *of_node_get(struct device_node *node)
 {
 	return node;
 }
-static inline void of_node_put(struct device_node *node)
-{
-}
-#else
-extern struct device_node *of_node_get(struct device_node *node);
-extern void of_node_put(struct device_node *node);
-#endif
+static inline void of_node_put(struct device_node *node) { }
+#endif /* !CONFIG_OF_DYNAMIC */
 
 #ifdef CONFIG_OF