modules: openthread: use PSA API by default

Make CONFIG_OPENTHREAD_CRYPTO_PSA as enabled by default in order to use
PSA Crypto API instead of legacy Mbed TLS' crypto. This is done with the
final goal to deprecate and remove usage of legacy crypto support in
the near future from Zephyr codebase.

Signed-off-by: Valerio Setti <[email protected]>

Author: valeriosetti

doc/releases/migration-guide-4.3.rst

@@ -530,6 +530,8 @@ OpenThread
   This requires the backend for Secure Storage (Settings, ZMS or a custom one)
   to be configured.
 
+* :kconfig:option:`CONFIG_OPENTHREAD_CRYPTO_PSA` is now enabled by default.
+
 Trusted Firmware-M
 ==================
 

modules/openthread/Kconfig

@@ -241,13 +241,17 @@ endif # OPENTHREAD_SECURITY_DEFAULT_CONFIG
 
 config OPENTHREAD_CRYPTO_PSA
 	bool "PSA Crypto API"
+	default y
 	select PSA_CRYPTO
 	select SECURE_STORAGE if !BUILD_WITH_TFM
 	select OPENTHREAD_PLATFORM_KEY_REF if !OPENTHREAD_COPROCESSOR_RCP
 	imply OPENTHREAD_PLATFORM_KEYS_EXPORTABLE_ENABLE
 	help
 	  Enable crypto backend library implementation based on PSA Crypto API
 	  instead of the default, using Mbed TLS.
+	  Warning: disabling this Kconfig (enabled by default) and falling back
+	  to legacy Mbed TLS crypto API is deprecated and will be removed in the
+	  future.
 
 config OPENTHREAD_MBEDTLS_LIB_NAME
 	string "mbedtls lib name"