sparc: remove not required includes from dma-mapping.h

The only thing we need to explicitly pull in is the defines for the
CPU type.

Signed-off-by: Christoph Hellwig <[e-mail]>
Acked-by: David S. Miller <[e-mail]>

arch/sparc/include/asm/dma-mapping.h

···
 #ifndef ___ASM_SPARC_DMA_MAPPING_H
 #define ___ASM_SPARC_DMA_MAPPING_H
 
-#include <linux/scatterlist.h>
-#include <linux/mm.h>
-#include <linux/dma-debug.h>
+#include <asm/cpu_type.h>
 
 extern const struct dma_map_ops *dma_ops;