mlx4_core: Wait 1 second after reset before accessing device

Put a 1000 msec delay after resetting the device before attempting to
do config cycles on it.  Not waiting causes system hangs on some
chipsets, e.g. Intel E7520, when the driver is loaded.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>