of: add 'of_' prefix to machine_is_compatible()

machine is compatible is an OF-specific call.  It should have
the of_ prefix to protect the global namespace.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Michal Simek <monstr@monstr.eu>
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index 8118d45..fbf2961 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -85,7 +85,7 @@
 extern void finish_device_tree(void);
 extern void unflatten_device_tree(void);
 extern void early_init_devtree(void *);
-extern int machine_is_compatible(const char *compat);
+extern int of_machine_is_compatible(const char *compat);
 extern void print_properties(struct device_node *node);
 extern int prom_n_intr_cells(struct device_node* np);
 extern void prom_get_irq_senses(unsigned char *senses, int off, int max);