fix(nvs_flash): Remove the forceful selection of NVS_ENCRYPTION with flash encryption

- This change will introduce a breaking change for SoCs with the HMAC
  peripheral. Turning on flash encryption will no longer enable NVS
  encryption automatically.

Closes https://github.com/espressif/esp-idf/issues/12549

docs/en/migration-guides/release-5.x/5.2/index.rst

@@ -9,5 +9,6 @@ Migration from 5.1 to 5.2
     gcc
     peripherals
     protocols
+    storage
     system
     wifi

docs/en/migration-guides/release-5.x/5.2/storage.rst

@@ -0,0 +1,11 @@
+Storage
+=======
+
+:link_to_translation:`zh_CN:[中文]`
+
+NVS Encryption
+--------------
+
+- For SoCs with the HMAC peripheral (``SOC_HMAC_SUPPORTED``), turning on :doc:`Flash Encryption <../../../security/flash-encryption>` will no longer automatically turn on :doc:`NVS encryption <../../../api-reference/storage/nvs_encryption>`.
+- You will need to explicitly turn on NVS encryption and select the required scheme (flash encryption-based or HMAC peripheral-based). You can select the HMAC peripheral-based scheme (:ref:`CONFIG_NVS_SEC_KEY_PROTECTION_SCHEME`), even if flash encryption is not enabled.
+- SoCs without the HMAC peripheral will still automatically turn on NVS encryption when flash encryption is enabled.