bnxt_en: Add devlink health reset reporter.

Add devlink health reporter for the firmware reset event.  Once we get
the notification from firmware about the impending reset, the driver
will report this to devlink and the call to bnxt_fw_reset() will be
initiated to complete the reset sequence.

Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>