wifi: iwlwifi: use PNVM data embedded in .ucode files

Given compatibility issues with external PNVM data that doesn't match
the firmware it was designed with/for, future firmware releases will
include the PNVM data in the firmware files directly, avoiding those
mismatch issues. Make the driver load and use that embedded PNVM data
in preference of external files, falling back to the external file if
it isn't present.

Co-developed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20250709081300.c843f77aa2d3.I7200f8dd40ef82aff1f5574fdd3966913cda592c@changeid