net/bnxt: fix probe in FreeBSD

net/bnxt: fix probe in FreeBSD

In FreeBSD environment, nic_uio driver does not support interrupts
and rte_intr_callback_register() will fail to register interrupts
which in turn causes bnxt driver probe failure.

Fixed driver to ignore interrupt callback failures in FreeBSD.
Also fixed to not use a dedicated completion ring for async events
from FW and process these events on RXQ0 in FreeBSD.

Fixes: 6de4c538b393 ("net/bnxt: fix error handling in port start")
Fixes: 43f78b380f89 ("net/bnxt: retry IRQ callback deregistration")
Cc: stable@dpdk.org
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reviewed-by: Santoshkumar Karanappa Rastapur <santosh.rastapur@broadcom.com>