iwlwifi: mvm: NVM - increase max section size

Section size limitation to 6000 is incorrect.
NVM file need to support bigger sections in order
to support PAPD tables.

Signed-off-by: Idan Kahlon <idanx.kahlon@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: Maor Perez <maorx.perez@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>