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/api-reference/storage/nvs_encryption.rst

@@ -20,7 +20,13 @@ NVS Encryption: Flash Encryption-Based Scheme
 
 In this scheme, the keys required for NVS encryption are stored in yet another partition, which is protected using :doc:`Flash Encryption <../../security/flash-encryption>`. Therefore, enabling :doc:`Flash Encryption <../../security/flash-encryption>` becomes a prerequisite for NVS encryption here.
 
-NVS encryption is enabled by default when :doc:`../../security/flash-encryption` is enabled. This is done because Wi-Fi driver stores credentials (like SSID and passphrase) in the default NVS partition. It is important to encrypt them as default choice if platform level encryption is already enabled.
+.. only:: SOC_HMAC_SUPPORTED
+
+    NVS encryption should be enabled when :doc:`../../security/flash-encryption` is enabled because the Wi-Fi driver stores credentials (like SSID and passphrase) in the default NVS partition. It is important to encrypt them if platform level encryption is already enabled.
+
+.. only:: not SOC_HMAC_SUPPORTED
+
+    NVS encryption is enabled by default when :doc:`../../security/flash-encryption` is enabled. This is done because Wi-Fi driver stores credentials (like SSID and passphrase) in the default NVS partition. It is important to encrypt them as default choice if platform level encryption is already enabled.
 
 For using NVS encryption using this scheme, the partition table must contain the :ref:`nvs_encr_key_partition`. Two partition tables containing the :ref:`nvs_encr_key_partition` are provided for NVS encryption under the partition table option (``menuconfig`` > ``Partition Table``). They can be selected with the project configuration menu (``idf.py menuconfig``). Please refer to the example :example:`security/flash_encryption` for how to configure and use the NVS encryption feature.
 

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.

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

@@ -9,5 +9,6 @@
     gcc
     peripherals
     protocols
+    storage
     system
     wifi

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

@@ -0,0 +1 @@
+.. include:: ../../../../en/migration-guides/release-5.x/5.2/storage.rst