net/mlx5_core: Wait for FW readiness on startup

On device initialization, wait till firmware indicates that that it is done
with initialization before proceeding to initialize the device.

Also update initialization segment layout to match driver/firmware
interface definitions.

Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>