cxgbe(4): Add support for high priority filters on T6+. They have their
own region in the TCAM starting with T6, unlike previous chips where
they were in the same region as normal filters.

These filters "hit" before anything else in the LE's lookup. The exact
order is:
a) High priority filters
b) TOE's active region (TCAM and/or hash)
c) Servers (TOE hw listeners)
d) Normal filters

MFC after: 1 week
Sponsored by: Chelsio Communications