tg3: Add tx and rx ring resource tracking

This patch adds code to assign status block, tx producer ring and rx
return ring resources needed for the other interrupt vectors.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>