Update Mbed TLS to 3.5.1

Commit ab5707185a9e ("Add a minimum rsa key size config to psa config")
introduced a minimal RSA key size condition to prevent accidental
misuse. The limit is set to 1024 bits and generating shorter RSA keys
will result in PSA_ERROR_NOT_SUPPORTED. Increase key size crypto tests
in TS service test to pass this check.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I917d0bf572fbf763a68c6d479d23ba66e9da6c13
diff --git a/components/app/ts-demo/ts-demo.cpp b/components/app/ts-demo/ts-demo.cpp
index 58b28ef..589f3b6 100644
--- a/components/app/ts-demo/ts-demo.cpp
+++ b/components/app/ts-demo/ts-demo.cpp
@@ -169,7 +169,7 @@
         psa_set_key_usage_flags(&attributes, PSA_KEY_USAGE_ENCRYPT | PSA_KEY_USAGE_DECRYPT);
         psa_set_key_algorithm(&attributes, PSA_ALG_RSA_PKCS1V15_CRYPT);
         psa_set_key_type(&attributes, PSA_KEY_TYPE_RSA_KEY_PAIR);
-        psa_set_key_bits(&attributes, 256);
+        psa_set_key_bits(&attributes, 1024);
 
         if (m_verbose) printf("Generating RSA encryption key");