mlx5: avoid 64-bit division

Commit 25c13324d03d ("IB/mlx5: Add steering SW ICM device memory type")
breaks i386 build by introducing three 64-bit divisions. As the divisor is
MLX5_SW_ICM_BLOCK_SIZE() which is always a power of 2, we can replace the
division with bit operations.

Fixes: 25c13324d03d ("IB/mlx5: Add steering SW ICM device memory type")
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index abac70a..340290b 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -2344,7 +2344,7 @@ static int handle_alloc_dm_sw_icm(struct ib_ucontext *ctx,
 	/* Allocation size must a multiple of the basic block size
 	 * and a power of 2.
 	 */
-	act_size = roundup(attr->length, MLX5_SW_ICM_BLOCK_SIZE(dm_db->dev));
+	act_size = round_up(attr->length, MLX5_SW_ICM_BLOCK_SIZE(dm_db->dev));
 	act_size = roundup_pow_of_two(act_size);
 
 	dm->size = act_size;