net/bnxt: fix PTP support for Thor

net/bnxt: fix PTP support for Thor

On Thor, Rx timestamp is present in the Rx completion record.
Only 32 bits of the timestamp is present in the completion.
The driver needs to periodically poll the current 48 bit
free running timer using the HWRM_PORT_TS_QUERY command.
It can combine the upper 16 bits from the HWRM response
with the lower 32 bits in the Rx completion to produce
the 48 bit timestamp for the Rx packet.

This patch adds an alarm thread to periodically poll the current 48 bit
free running timer using the HWRM_PORT_TS_QUERY command.
This avoids issuing the hwrm command from the Rx handler.
This patch also handles the timer roll over condition.

Fixes: 6cbd89f9f3d8 ("net/bnxt: support PTP for Thor")
Cc: stable@dpdk.org
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Lance Richardson <lance.richardson@broadcom.com>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>