bnxt_en: Implement new scheme to reserve tx rings.

bnxt_en: Implement new scheme to reserve tx rings.

Orabug: 25645429

In order to properly support TX rate limiting in SRIOV VF functions or
NPAR functions, firmware needs better control over tx ring allocations.
The new scheme requires the driver to reserve the number of tx rings
and to query to see if the requested number of tx rings is reserved.
The driver will use the new scheme when the firmware interface spec is
1.6.1 or newer.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 391be5c2736456f032fe0265031ecfe17aee84a0)
Signed-off-by: Brian Maly <brian.maly@oracle.com>