iommu-common: move to arch/sparc

This code is only used by sparc, and all new iommu drivers should use the
drivers/iommu/ framework.  Also remove the unused exports.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>

arch/sparc/include/asm/iommu_64.h

@@ -17,7 +17,7 @@
 #define IOPTE_WRITE   0x0000000000000002UL
 
 #define IOMMU_NUM_CTXS	4096
-#include <linux/iommu-common.h>
+#include <asm/iommu-common.h>
 
 struct iommu_arena {
 	unsigned long	*map;