[BNX2]: Improve handshake with firmware

Improve handshake with bootcode with the following changes:

1. Increase timeout to 100msec and use msleep instead of udelay.

2. Add more error checking for timeouts and errors. 

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