bnxt_en: Make PTP TX timestamp HWRM query silent

In a busy network, especially with flow control enabled, we may
experience timestamp query failures fairly regularly. After a while,
dmesg may be flooded with timestamp query failure error messages.

Silence the error message from the low level hwrm function that
sends the firmware message.  Change netdev_err() to netdev_WARN_ONCE()
if this FW call ever fails.

Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/r/20231212005122.2401-14-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>