tinycrypt: deprecate the library

Since we now have PSA Crypto APIs/Mbed TLS alternatives for crypto
operations in all Zephyr's codebase we can start the deprecation
of the TinyCrypt libary (as planned from zephyrproject-rtos#43712).

Signed-off-by: Valerio Setti <vsetti@baylibre.com>

doc/releases/migration-guide-4.0.rst

@@ -69,6 +69,18 @@ Mbed TLS
   corresponding build symbol was removed in Mbed TLS 3.1.0 and is now assumed to
   be enabled. (:github:`77657`)
 
+TinyCrypt
+=========
+
+* Starting from this release the library is being marked as deprecated (:github:`79566`).
+  The reasons for this are that (:github:`43712``):
+  * the upstream version of this library is unmaintained
+  * reduce the number of crypto libraries available in Zephyr (currently there are
+    3 different implementations: TinyCrypt, MbedTLS and PSA Crypto APIs).
+
+  PSA Crypto APIs are proposed as the de-facto standard for the future to perform
+  crypto operations.
+
 Trusted Firmware-M
 ==================
 

doc/releases/release-notes-4.0.rst

@@ -52,6 +52,15 @@ Deprecated in this release
 
 * The :ref:`kscan_api` subsystem has been marked as deprecated.
 
+* Starting from this release the library is being marked as deprecated (:github:`79566`).
+  The reasons for this are that (:github:`43712``):
+  * the upstream version of this library is unmaintained
+  * reduce the number of crypto libraries available in Zephyr (currently there are
+    3 different implementations: TinyCrypt, MbedTLS and PSA Crypto APIs).
+
+  PSA Crypto APIs are proposed as the de-facto standard for the future to perform
+  crypto operations.
+
 Architectures
 *************
 

modules/Kconfig.tinycrypt

@@ -9,6 +9,7 @@ config ZEPHYR_TINYCRYPT_MODULE
 config TINYCRYPT
 	bool "TinyCrypt Support"
 	depends on ZEPHYR_TINYCRYPT_MODULE
+	select DEPRECATED
 	help
 	  This option enables the TinyCrypt cryptography library.