selftests: mlxsw: Add target for tc flower test on spectrum

Add a wrapper around mlxsw/tc_flower_scale.sh that parameterizes the
generic tc flower scale test template with Spectrum-specific target
values.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Yuval Mintz <yuvalm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/drivers/net/mlxsw/spectrum/tc_flower_scale.sh

+# SPDX-License-Identifier: GPL-2.0
+source ../tc_flower_scale.sh
+
+tc_flower_get_target()
+{
+	local should_fail=$1; shift
+
+	# 6144 (6x1024) is the theoretical maximum.
+	# One bank of 512 rules is taken by the 18-byte MC router rule.
+	# One rule is the ACL catch-all.
+	# 6144 - 512 - 1 = 5631
+	local target=5631
+
+	if ((! should_fail)); then
+		echo $target
+	else
+		echo $((target + 1))
+	fi
+}