modules: mbedtls: add promptless CONFIG_MBEDTLS_PSA_CRYPTO_STORAGE_C

Add a Kconfig option to match the Mbed TLS define
instead of defining it based on CONFIG_SECURE_STORAGE.

This gives more flexibility regarding the potential re-definition of the
CONFIG_MBEDTLS_PSA_CRYPTO_STORAGE_C Kconfig option.

Signed-off-by: Tomi Fontanilles <tomi.fontanilles@nordicsemi.no>

modules/mbedtls/Kconfig.tls-generic

@@ -585,6 +585,9 @@ config MBEDTLS_PSA_P256M_DRIVER_RAW
 	  Warning: Usage of this Kconfig option is prohibited in Zephyr's codebase.
 	           Users can enable it in case of very memory-constrained devices, but be aware that the p256-m interface is absolutely not guaranted to remain stable over time.
 
+config MBEDTLS_PSA_CRYPTO_STORAGE_C
+	bool
+
 config MBEDTLS_PSA_STATIC_KEY_SLOTS
 	bool "Use statically allocated key buffers to store key material"
 	default y if !MBEDTLS_ENABLE_HEAP

modules/mbedtls/configs/config-tls-generic.h

@@ -477,17 +477,16 @@
 #if defined(CONFIG_MBEDTLS_PSA_CRYPTO_C)
 #define MBEDTLS_PSA_CRYPTO_C
 #define MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS
+#endif
 
 #if defined(CONFIG_MBEDTLS_PSA_P256M_DRIVER_ENABLED)
 #define MBEDTLS_PSA_P256M_DRIVER_ENABLED
 #endif
 
-#if defined(CONFIG_SECURE_STORAGE)
+#if defined(CONFIG_MBEDTLS_PSA_CRYPTO_STORAGE_C)
 #define MBEDTLS_PSA_CRYPTO_STORAGE_C
 #endif
 
-#endif /* CONFIG_MBEDTLS_PSA_CRYPTO_C */
-
 #if defined(CONFIG_MBEDTLS_PSA_STATIC_KEY_SLOTS)
 #define MBEDTLS_PSA_STATIC_KEY_SLOTS
 #endif

subsys/secure_storage/Kconfig

@@ -4,6 +4,7 @@
 menuconfig SECURE_STORAGE
 	bool "Secure storage subsystem"
 	depends on !BUILD_WITH_TFM
+	select MBEDTLS_PSA_CRYPTO_STORAGE_C if MBEDTLS_PSA_CRYPTO_C
 	select EXPERIMENTAL
 	help
 	  The secure storage subsystem provides an implementation of the PSA Secure Storage API