NFC not working for nrf5340dk after nrf-sdk 2.7.0

[ovaneg]

Hi,

Recently we upgraded to nrf-sdk 2.7.0 (previously on 2.6.1) and I began to notice that NFC had stopped working for our project, when running on nrf5340dk.

While switching between versions of nrf-sdk I tested this behaviour on nordic NFC samples, such as Writable NDEF Message.
Building this sample on nrf-sdk 2.6.1 I was able to successfully build & flash to the application core, and read the tag with an NFC tools app. When performing these exact steps with nrf-sdk 2.7.0 I was unable to read the tag, despite everything appearing to work as intended according to console logs.

[ovaneg]

It appears that NFC was changed to default to off between zephyr releases. Manually enabling `&nfct` in a board overlay appears to have fixed the issue.

Also noteworthy: I had to mass erase in order for this solution to work. Whether this is because of the sample, or because something has gone wrong in my own project is unclear