Blackfin arch: export symbol get_dma_curr_desc_ptr for driver usage

Signed-off-by: NCliff Cai <cliff.cai@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

arch/blackfin/kernel/bfin_dma_5xx.c

@@ -436,6 +436,7 @@ unsigned long get_dma_curr_desc_ptr(unsigned int channel)
 
 	return dma_ch[channel].regs->curr_desc_ptr;
 }
+EXPORT_SYMBOL(get_dma_curr_desc_ptr);
 
 unsigned long get_dma_curr_addr(unsigned int channel)
 {