arm,arm64/include/asm/io.h: define struct bio_vec

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index c45effc..3c597c2 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -374,6 +374,7 @@
 #define BIOVEC_MERGEABLE(vec1, vec2)	\
 	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
 
+struct bio_vec;
 extern bool xen_biovec_phys_mergeable(const struct bio_vec *vec1,
 				      const struct bio_vec *vec2);
 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)				\