qlcnic: Use flt method to determine flash fw region

Use flash layout table to get flash fw starting address and its size.
If that fails, use legacy method.

Signed-off-by: Sritej Velaga <sritej.velaga@qlogic.com>
Signed-off-by: Anirban Chakraborty <anirban.chakraborty@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>