nommu: Do not export the copy/clear user page functions

The __cpu_{clear|copy}_user_page functions are not defined for the
MMU-less case and therefore should not be exported.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm/mm/proc-syms.c

@@ -31,12 +31,14 @@ EXPORT_SYMBOL(__cpuc_coherent_kern_range);
 EXPORT_SYMBOL(cpu_cache);
 #endif
 
+#ifdef CONFIG_MMU
 #ifndef MULTI_USER
 EXPORT_SYMBOL(__cpu_clear_user_page);
 EXPORT_SYMBOL(__cpu_copy_user_page);
 #else
 EXPORT_SYMBOL(cpu_user);
 #endif
+#endif
 
 /*
  * No module should need to touch the TLB (and currently