Increase heapsize for mbedtls library

The mbedTLS library requires larger heap memory for verification of RSASSA-PSS
signature in certificates during Trusted Board Boot. This patch increases the
heap memory for the same.

Change-Id: I3c3123d7142b7b7b01463516ec436734895da159
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

drivers/auth/mbedtls/mbedtls_common.c

@@ -16,7 +16,7 @@
 #if (TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_ECDSA)
 #define MBEDTLS_HEAP_SIZE		(14*1024)
 #elif (TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_RSA)
-#define MBEDTLS_HEAP_SIZE		(6*1024)
+#define MBEDTLS_HEAP_SIZE		(7*1024)
 #endif
 static unsigned char heap[MBEDTLS_HEAP_SIZE];