bnxt_en: Add an upper bound for all firmware command timeouts.

The timeout period for firmware messages is passed to the driver
from the firmware in the response of the first command.  This
timeout period is multiplied by a factor for certain long
running commands such as NVRAM commands.  In some cases, the
timeout period can become really long and it can cause hung task
warnings if firmware has crashed or is not responding.  To avoid
such long delays, cap all firmware commands to a max timeout value
of 40 seconds.

Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>