iwlwifi: nvm: force mac from otp in case nvm mac is reserved

Take the MAC address from the OTP even if one is present in
the NVM, if that MAC address happens to be a reserved one.

Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>