SST: Crypto service binding

Refactors the SST crypto interface to call into the Crypto service
instead of Mbed TLS. Removes the Mbed TLS build from the SST build
files.

Change-Id: Iff3bdf799c66127c7b71a9f5a8c54e887134a8e8
Signed-off-by: Jamie Fox <jamie.fox@arm.com>
diff --git a/secure_fw/services/crypto/crypto_init.c b/secure_fw/services/crypto/crypto_init.c
index 596d2fc..e68090b 100644
--- a/secure_fw/services/crypto/crypto_init.c
+++ b/secure_fw/services/crypto/crypto_init.c
@@ -47,7 +47,7 @@
  *        in bytes
  */
 #ifndef TFM_CRYPTO_IOVEC_BUFFER_SIZE
-#define TFM_CRYPTO_IOVEC_BUFFER_SIZE (1024)
+#define TFM_CRYPTO_IOVEC_BUFFER_SIZE (5120)
 #endif
 
 /**