net/nfp: create separate entity for PF device

net/nfp: create separate entity for PF device

Before this change memory for the private data of all physical ports
where allocated with single rte_zmalloc() call. Specific port private
data was accessed by means of an offset into this memory. This scheme is
problematic when attempting to free only one port's private data at a
time.

To address this, a new entity is created called struct nfp_pf_dev. This
struct represents the PF device. It has a number of PF specific members.
Notably it has a pointer of type rte_eth_dev that points to the eth_dev
associated with the first physical port of the device. It also has an
array of nfp_net_hw's containing pointers to all the physical ports
under the PF.

Memory is first allocated for the PF and PF specific initialization is
attempted. Next, all the physical ports under the PF is iterated and
memory is allocated separately for the private data of each port. Port 0
is skipped during this phase because memory has already been allocated
and an eth_dev already exits for the 0th port.

Signed-off-by: Heinrich Kuhn <heinrich.kuhn@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Louis Peens <louis.peens@netronome.com>