Blackfin arch: Add definition of dma_mapping_error

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

include/asm-blackfin/dma-mapping.h

@@ -15,6 +15,8 @@ void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
 #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
 #define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
 
+#define dma_mapping_error
+
 /*
  * Map a single buffer of the indicated size for DMA in streaming mode.
  * The 32-bit bus address to use is returned.