iwlwifi: nvm: set the correct offsets to 3168 series

The driver currently handles two NVM formats,
one for 7000 family and below, and one for 8000 family and above.
The 3168 series uses something in between,
so currently the driver uses incorrect offsets for it.
Fix the incorrect offsets.

Fixes: c4836b05

 ("iwlwifi: Add PCI IDs for the new 3168 series")
Signed-off-by: Chaya Rachel Ivgi <chaya.rachel.ivgi@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>