mlxsw: spectrum_buffers: Further reduce pool size on Spectrum-2

In commit e891ce1d ("mlxsw: spectrum_buffers: Reduce pool size on
Spectrum-2"), pool size was reduced to mitigate a problem in port buffer
usage of ports split four ways. It turns out that this work around does not
solve the issue, and a further reduction is required.

Thus reduce the size of pool 0 by another 2.7 MiB, and round down to the
whole number of cells.

Fixes: e891ce1d ("mlxsw: spectrum_buffers: Reduce pool size on Spectrum-2")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_buffers.c

@@ -437,8 +437,8 @@ static const struct mlxsw_sp_sb_pr mlxsw_sp1_sb_prs[] = {
 			   MLXSW_SP1_SB_PR_CPU_SIZE, true, false),
 };
 
-#define MLXSW_SP2_SB_PR_INGRESS_SIZE	38128752
-#define MLXSW_SP2_SB_PR_EGRESS_SIZE	38128752
+#define MLXSW_SP2_SB_PR_INGRESS_SIZE	35297568
+#define MLXSW_SP2_SB_PR_EGRESS_SIZE	35297568
 #define MLXSW_SP2_SB_PR_CPU_SIZE	(256 * 1000)
 
 /* Order according to mlxsw_sp2_sb_pool_dess */