ionic: contiguous memory for notifyq

The event notification queue is set up a little differently in the
NIC and so the notifyq q and cq descriptor structures need to be
contiguous, which got missed in an earlier patch that separated
out the q and cq descriptor allocations.  That patch was aimed at
making the big tx and rx descriptor queue allocations easier to
manage - the notifyq is much smaller and doesn't need to be split.
This patch simply adds an if/else and slightly different code for
the notifyq descriptor allocation.

Fixes: ea5a8b09 ("ionic: reduce contiguous memory allocation requirement")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>