net: mvpp2: cls: Rename the flow table macros

The Flow Table dictates what lookups will be issued for each flow type.
The lookup sequence for each flow is similar, and the index of each
lookup is computed by some macros.

There are similar mechanisms for the C2 TCAM lookups, so in order to
avoid confusion, rename the flow table index computing macros with a
common prefix.

The only difference in behaviour is that we now use the very first entry
in the flow for the RSS lookup (the first entry was previously unused).

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>