nrf_security: Mbedlts threading dependency fix

Make the MbedTLS threading configuration to depend on
the multithreading Kconfig option. The multithreading
configuration is required by both the PSA crypto
implementation which uses the Zephyr mutexes and
also by the MbedTLS legacy implementation which
may not use Zephyr mutexes for CC3XX.

Signed-off-by: Georgios Vasilakis <[email protected]>
(cherry picked from commit 1e65489)

Author: Vge0rge

subsys/nrf_security/Kconfig.legacy

@@ -23,6 +23,7 @@ config MBEDTLS_MEMORY_BUFFER_ALLOC_C
 config MBEDTLS_THREADING_C
 	bool "Threading support for Mbed TLS and PSA crypto"
 	default y if CC3XX_BACKEND || MBEDTLS_PSA_CRYPTO_C
+	depends on MULTITHREADING
 	help
 	  Threading support is used when PSA crypto is built locally or
 	  when legacy APIs implemented using CryptoCell is in use.