tg3: Refine APE status check

Recently, more status bits have been added to the APE status register.
This patch refines the status register check so that the driver can
send more events than it would have otherwise.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>