SPARC64: fix iommu sg chaining

Commit 2c941a204070ab32d92d40318a3196a7fb994c00 looks incomplete. The
helper functions like prepare_sg() need to support sg chaining too.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/arch/sparc64/kernel/iommu_common.h b/arch/sparc64/kernel/iommu_common.h
index ad79101..75b5a58 100644
--- a/arch/sparc64/kernel/iommu_common.h
+++ b/arch/sparc64/kernel/iommu_common.h
@@ -8,6 +8,7 @@
 #include <linux/types.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
+#include <linux/scatterlist.h>
 
 #include <asm/iommu.h>
 #include <asm/scatterlist.h>