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/kernel/ldc.c

@@ -16,7 +16,7 @@
 #include <linux/list.h>
 #include <linux/init.h>
 #include <linux/bitmap.h>
-#include <linux/iommu-common.h>
+#include <asm/iommu-common.h>
 
 #include <asm/hypervisor.h>
 #include <asm/iommu.h>