ARM: Reduce __flush_dcache_page() visibility

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index c4f6f05..a888363 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -24,6 +24,8 @@
 
 const struct mem_type *get_mem_type(unsigned int type);
 
+extern void __flush_dcache_page(struct address_space *mapping, struct page *page);
+
 #endif
 
 struct map_desc;