Add support for RSASSAPSS algorithm in mbedtls crypto driver

This patch adds support for RSASSA-PSS Signature Algorithm for
X509 certificates in mbedtls crypto driver. Now the driver supports
RSA PKCS2_1 standard as mandated by TBBR.

NOTE: With this patch, the PKCS1_5 standard compliant RSA signature
is deprecated.

Change-Id: I9cf6d073370b710cc36a7b374a55ec96c0496461
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
diff --git a/include/drivers/auth/mbedtls/mbedtls_config.h b/include/drivers/auth/mbedtls/mbedtls_config.h
index 22e7574..0a05886 100644
--- a/include/drivers/auth/mbedtls/mbedtls_config.h
+++ b/include/drivers/auth/mbedtls/mbedtls_config.h
@@ -22,12 +22,15 @@
 /* Prevent mbed TLS from using snprintf so that it can use tf_snprintf. */
 #define MBEDTLS_PLATFORM_SNPRINTF_ALT
 
+#if !ERROR_DEPRECATED
 #define MBEDTLS_PKCS1_V15
+#endif
 #define MBEDTLS_PKCS1_V21
 
 #define MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION
 #define MBEDTLS_X509_CHECK_KEY_USAGE
 #define MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE
+#define MBEDTLS_X509_RSASSA_PSS_SUPPORT
 
 #define MBEDTLS_ASN1_PARSE_C
 #define MBEDTLS_ASN1_WRITE_C