nds32: don't export low-level cache flushing routines

None of these is used by modules.  Nor should they as we have better
highlevel primitives.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>

arch/nds32/kernel/nds32_ksyms.c

@@ -23,9 +23,3 @@ EXPORT_SYMBOL(memzero);
 EXPORT_SYMBOL(__arch_copy_from_user);
 EXPORT_SYMBOL(__arch_copy_to_user);
 EXPORT_SYMBOL(__arch_clear_user);
-
-/* cache handling */
-EXPORT_SYMBOL(cpu_icache_inval_all);
-EXPORT_SYMBOL(cpu_dcache_wbinval_all);
-EXPORT_SYMBOL(cpu_dma_inval_range);
-EXPORT_SYMBOL(cpu_dma_wb_range);