event/dlb2: add v2.5 sequence number management

event/dlb2: add v2.5 sequence number management

Update the low level HW functions that perform the sequence number
management functions. These include getting a groups number of
sequence numbers per queue, managing in-use slots, getting the
current occupancy, and setting sequence numbers for a group.

The logic is very similar to what was done for v2.0,
but the new combined register map for v2.0 and v2.5
uses new register names and bit names.  Additionally,
new register access macros are used so that the code
can perform the correct action, based on the hardware.

Signed-off-by: Timothy McDaniel <timothy.mcdaniel@intel.com>