ARM: 6378/1: Allow lazy cache flushing via PG_arch_1 for highmem pages

Commit d73cd428 forced non-lazy cache flushing of highmem pages in
flush_dcache_page(). This isn't needed since __flush_dcache_page()
(called lazily from update_mmu_cache) can handle highmem pages (fixed by
commit 7e5a69e8).
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/flush.c

@@ -247,7 +247,7 @@ void flush_dcache_page(struct page *page)
 	mapping = page_mapping(page);
 
 #ifndef CONFIG_SMP
-	if (!PageHighMem(page) && mapping && !mapping_mapped(mapping))
+	if (mapping && !mapping_mapped(mapping))
 		set_bit(PG_dcache_dirty, &page->flags);
 	else
 #endif