mlx5: avoid 64-bit division in dr_icm_pool_mr_create()

Recently added code introduces 64-bit division in dr_icm_pool_mr_create()
so that build on 32-bit architectures fails with

  ERROR: "__umoddi3" [drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.ko] undefined!

As the divisor is always a power of 2, we can use bitwise operation
instead.

Fixes: 29cf8feb ("net/mlx5: DR, ICM pool memory allocator")
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx5/core/steering/dr_icm_pool.c

@@ -137,7 +137,8 @@ dr_icm_pool_mr_create(struct mlx5dr_icm_pool *pool,
 
 	icm_mr->icm_start_addr = icm_mr->dm.addr;
 
-	align_diff = icm_mr->icm_start_addr % align_base;
+	/* align_base is always a power of 2 */
+	align_diff = icm_mr->icm_start_addr & (align_base - 1);
 	if (align_diff)
 		icm_mr->used_length = align_base - align_diff;