sparc: Create common header file for prom_{32,64}.c

This is where common declarations will go as we unify
these files as much as possible into common code.
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/kernel/prom.h

+#ifndef __PROM_H
+#define __PROM_H
+
+#include <linux/spinlock.h>
+#include <asm/prom.h>
+
+extern struct device_node *allnodes;	/* temporary while merging */
+extern rwlock_t devtree_lock;	/* temporary while merging */
+
+#endif /* __PROM_H */

arch/sparc/kernel/prom_32.c

@@ -25,9 +25,7 @@
 #include <asm/prom.h>
 #include <asm/oplib.h>
 
-extern struct device_node *allnodes;	/* temporary while merging */
-
-extern rwlock_t devtree_lock;	/* temporary while merging */
+#include "prom.h"
 
 struct device_node *of_find_node_by_phandle(phandle handle)
 {

arch/sparc/kernel/prom_64.c

@@ -30,9 +30,7 @@
 #include <asm/upa.h>
 #include <asm/smp.h>
 
-extern struct device_node *allnodes;	/* temporary while merging */
-
-extern rwlock_t devtree_lock;	/* temporary while merging */
+#include "prom.h"
 
 struct device_node *of_find_node_by_phandle(phandle handle)
 {