arm: remove the unused BIOVEC_MERGEABLE define

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

arch/arm/include/asm/io.h

@@ -459,13 +459,6 @@ extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
 
 #include <asm-generic/io.h>
 
-/*
- * can the hardware map this into one segment or not, given no other
- * constraints.
- */
-#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);