mm/CRIS: clean up unused VALID_PAGE()

VALID_PAGE() has been removed from kernel long time ago, so clean up it.
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/cris/include/asm/page.h

@@ -51,7 +51,6 @@ typedef struct page *pgtable_t;
  */ 
 
 #define virt_to_page(kaddr)    (mem_map + (((unsigned long)(kaddr) - PAGE_OFFSET) >> PAGE_SHIFT))
-#define VALID_PAGE(page)       (((page) - mem_map) < max_mapnr)
 #define virt_addr_valid(kaddr)	pfn_valid((unsigned)(kaddr) >> PAGE_SHIFT)
 
 /* convert a page (based on mem_map and forward) to a physical address