crypto-client test: implement the first IPC call for psa_crypto_init()

This commit implements the first useful IPC communication between
the client and the server. The implemented command is simple,
psa_crypto_init(), and its return value is sent back to the client.

Note: the newly added file psa_functions_codes.h is temporary
and it's probably the one that needs to be automatically
generated by a python script to support all crypto functions.

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/tests/psa-client-server/psasim/include/psa/service.h b/tests/psa-client-server/psasim/include/psa/service.h
index c8c0024..b6c9684 100644
--- a/tests/psa-client-server/psasim/include/psa/service.h
+++ b/tests/psa-client-server/psasim/include/psa/service.h
@@ -17,6 +17,8 @@
 
 #include "psa/common.h"
 
+#include "psa/crypto.h"
+
 /********************** PSA Secure Partition Macros and Types ****************/
 
 /* PSA wait timeouts */