[ARM] Support write combining on framebuffers

drivers/video/fbmem.c

@@ -1111,13 +1111,11 @@ fb_mmap(struct file *file, struct vm_area_struct * vma)
 #elif defined(__mips__)
 	pgprot_val(vma->vm_page_prot) &= ~_CACHE_MASK;
 	pgprot_val(vma->vm_page_prot) |= _CACHE_UNCACHED;
-#elif defined(__arm__)
-	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 #elif defined(__sh__)
 	pgprot_val(vma->vm_page_prot) &= ~_PAGE_CACHABLE;
 #elif defined(__hppa__)
 	pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE;
-#elif defined(__ia64__)
+#elif defined(__ia64__) || defined(__arm__)
 	vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
 #else
 #warning What do we have to do here??