net/bnxt: fix performance for Arm

net/bnxt: fix performance for Arm

Eliminate unnecessary rte_smp_wmb() before writing to request/completion
doorbells. Use rte_cio_wmb() memory barrier instead of rte_io_wmb()
before writing to tx/rx request queue doorbells and use
rte_compiler_barrier() before writing to tx/rx completion queue
doorbells.

Fixes: 4af9d0c72941 ("net/bnxt: cleanup NQ doorbell")
Fixes: f8168ca0e690 ("net/bnxt: support thor controller")
Cc: stable@dpdk.org
Signed-off-by: Rahul Gupta <rahul.gupta@broadcom.com>
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reviewed-by: Lance Richardson <lance.richardson@broadcom.com>