netxen: Load firmware during probe, dma watchdog fix.

The firmware should be loaded after resetting hardware during PCI probe,
besides module unload. This fixes issue with 2nd port of multiport adapter
on powerpc blades. This patch also fixes a bug that PCI resources are not
freed if dma watchdog shutdown failed. The dma watchdog poll messages
during module unload are also suppressed.

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: Milan Bag <mbag@netxen.com>
Signed-off-by: Wen Xiong <wenxiong@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>