sch_cake: add RFC 8622 LE PHB support to CAKE diffserv handling

Change tin mapping on diffserv3, 4 & 8 for LE PHB support, in essence
making LE a member of the Bulk tin.

Bulk has the least priority and minimum of 1/16th total bandwidth in the
face of higher priority traffic.

NB: Diffserv 3 & 4 swap tin 0 & 1 priorities from the default order as
found in diffserv8, in case anyone is wondering why it looks a bit odd.
Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
[ reword commit message slightly ]
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_cake.c

@@ -312,8 +312,8 @@ static const u8 precedence[] = {
 };
 
 static const u8 diffserv8[] = {
-	2, 5, 1, 2, 4, 2, 2, 2,
-	0, 2, 1, 2, 1, 2, 1, 2,
+	2, 0, 1, 2, 4, 2, 2, 2,
+	1, 2, 1, 2, 1, 2, 1, 2,
 	5, 2, 4, 2, 4, 2, 4, 2,
 	3, 2, 3, 2, 3, 2, 3, 2,
 	6, 2, 3, 2, 3, 2, 3, 2,
@@ -323,7 +323,7 @@ static const u8 diffserv8[] = {
 };
 
 static const u8 diffserv4[] = {
-	0, 2, 0, 0, 2, 0, 0, 0,
+	0, 1, 0, 0, 2, 0, 0, 0,
 	1, 0, 0, 0, 0, 0, 0, 0,
 	2, 0, 2, 0, 2, 0, 2, 0,
 	2, 0, 2, 0, 2, 0, 2, 0,
@@ -334,7 +334,7 @@ static const u8 diffserv4[] = {
 };
 
 static const u8 diffserv3[] = {
-	0, 0, 0, 0, 2, 0, 0, 0,
+	0, 1, 0, 0, 2, 0, 0, 0,
 	1, 0, 0, 0, 0, 0, 0, 0,
 	0, 0, 0, 0, 0, 0, 0, 0,
 	0, 0, 0, 0, 0, 0, 0, 0,