From 9000 family on, we need to get HW address from host
CSR registers.
OEM can override it by fusing the override registers - read
those first, and if those are 0 - read the OTP registers instead.

In addition - bail out if no valid mac address is present. Make
it shared for all NICs.
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>