bnxt_en: Check context memory requirements from firmware.

New device requires host context memory as a backing store.  Call
firmware to check for context memory requirements and store the
parameters.  Allocate host pages accordingly.

We also need to move the call bnxt_hwrm_queue_qportcfg() earlier
so that all the supported hardware queues and the IDs are known
before checking and allocating context memory.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>