bnxt_en: Retry sending the first message to firmware if it is under reset.

The first HWRM_VER_GET message to firmware during probe may timeout if
firmware is under reset.  This can happen during hot-plug for example.
On P5 and newer chips, we can check if firmware is in the boot stage by
reading a status register.  Retry 5 times if the status register shows
that firmware is not ready and not in error state.

Reviewed-by: Edwin Peer <edwin.peer@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>