[MIPS] Handle aliases in vmalloc correctly.

flush_cache_vmap / flush_cache_vunmap were calling flush_cache_all which -
having been deprecated - turned into a nop ...

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/mm/cache.c

@@ -30,6 +30,9 @@ void (*flush_cache_page)(struct vm_area_struct *vma, unsigned long page,
 	unsigned long pfn);
 void (*flush_icache_range)(unsigned long start, unsigned long end);
 
+void (*__flush_cache_vmap)(void);
+void (*__flush_cache_vunmap)(void);
+
 /* MIPS specific cache operations */
 void (*flush_cache_sigtramp)(unsigned long addr);
 void (*local_flush_data_cache_page)(void * addr);