tg3: Provide full regdump on tx timeout

The current amount of information provided in the output of a tx timeout
is insufficient to determine a root cause.  This patch replaces the
terse, four-register status output with a more complete body of
information.  For PCIe devices, the full register space is dumped.  For
other devices, select registers are dumped instead.

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