bnxt_en: Handle RESET_NOTIFY async event from firmware.

This event from firmware signals a coordinated reset initiated by the
firmware.  It may be triggered by some error conditions encountered
in the firmware or other orderly reset conditions.

We store the parameters from this event.  Subsequent patches will
add logic to handle reset itself using devlink reporters.

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>