Track: feed ELE_S4xx Zephyr NVM fixes back to NXP

[ajlennon]

Branch: dd/ele-s4xx-zephyr-nvm-rt118x (base NXP 90483da).

Used by DynamicDevices/zephyr-rt1186-f1 for FRDM RT1186 ELE opaque auth across OTA.

Intent: discuss with NXP; contribute a small evidence-backed patch set. Do not open an upstream PR until we have a focused write-up (failure mode → fix → EVK proof) and human review.

See BRANCH-NOTES.md on the branch and https://github.com/DynamicDevices/zephyr-rt1186-f1/issues/1