net/bnxt: support 58818 chip family

net/bnxt: support 58818 chip family

The new chip (Stingray 2) is part of the P5 chip family with a number
of changes:

1. Implement the epoch doorbell bit for 58818 chip. With the new
   doorbell infrastructure and the unbounded index logic, now set the
   epoch doorbell bit to support proper doorbell operation on the new
   chip.  Toggle epoch bit of all rings when it's wrapped to support
   doorbell overflow checking.
2. Get the legacy doorbell size from firmware. Legacy doorbell support
   has been removed in Stingray 2. So, the fast path doorbell pages
   start from the base of the BAR. Drivers need to use
   legacy_l2_db_space_size_kb field in the hwrm_func_qcfg_output
   response to get the legacy doorbell page offset from the BAR.
3. Set VALID doorbell bit on 58818 chip family. This class of chip has a
   valid doorbell bit added and it needs to be set.
4. Use "chip_num" returned by firmware. The "chip_num" field in the
   HWRM_VER_GET output returns the chip number. Use this value to
   identify chip category for 58818 chip family.
5. Added device ids for Stingray2 PF/VF devices.

Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>