Crypto: Update to use Mbed Crypto 1.1.0

This patch updates the interface to be able to use
Mbed Crypto 1.1.0. Also the build instructions are
updated.

Change-Id: Ic8edbda056fdb590eda03e4a6d069b11dfcc9769
Signed-off-by: Antonio de Angelis <antonio.deangelis@arm.com>
diff --git a/interface/include/psa/crypto_struct.h b/interface/include/psa/crypto_struct.h
index 3502bdc..12d1fc8 100644
--- a/interface/include/psa/crypto_struct.h
+++ b/interface/include/psa/crypto_struct.h
@@ -75,9 +75,10 @@
 {
     psa_key_usage_t usage;
     psa_algorithm_t alg;
+    psa_algorithm_t alg2;
 };
 
-#define PSA_KEY_POLICY_INIT {0, 0}
+#define PSA_KEY_POLICY_INIT {0, 0, 0}
 static inline struct psa_key_policy_s psa_key_policy_init( void )
 {
     const struct psa_key_policy_s v = PSA_KEY_POLICY_INIT;