bnxt_en: Implement new method to reserve rings.

The new method will call firmware to reserve the desired tx, rx, cmpl
rings, ring groups, stats context, and vnic resources.  A second query
call will check the actual resources that firmware is able to reserve.
The driver will then trim and adjust based on the actual resources
provided by firmware.  The driver will then reserve the final resources
in use.

This method is a more flexible way of using hardware resources.  The
resources are not fixed and can by adjusted by firmware.  The driver
adapts to the available resources that the firmware can reserve for
the driver.

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