[TG3]: Add parameter to tg3_halt

Add a reset kind parameter to tg3_halt() so that the RESET_KIND_SUSPEND
parameter can be passed to tg3_halt() before doing offline tests.

All other calls to tg3_halt() will use the RESET_KIND_SHUTDOWN
parameter.

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