bnx2: Fix shutdown sequence

bnx2: Fix shutdown sequence

The pci shutdown handler added in:

    bnx2: Add pci shutdown handler
    commit 25bfb1dd4ba3b2d9a49ce9d9b0cd7be1840e15ed

created a shutdown down sequence without chip reset if the device was
never brought up.  This can cause the firmware to shutdown the PHY
prematurely and cause MMIO read cycles to be unresponsive.  On some
systems, it may generate NMI in the bnx2's pci shutdown handler.

The fix is to tell the firmware not to shutdown the PHY if there was
no prior chip reset.

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