mbedtls: Namespace for TF specific macros

An earlier patch (arm-trusted-firmware#874) migrated MBEDTLS_ suffixed
macros to have a TBBR_ suffix to avoid any potential clash with future
mbedtls macros.

But on reflection the TBBR_ suffix could be confusing as the macros
are used to drive TF-specific configuration of mbedtls. As such
this patch migrates these macros from TBBR_suffix to TF_MBEDTLS_
suffix which more accurately conveys their use.

Change-Id: Ic87642b653ceeaa03d62f724976abd5e12e867d4
Signed-off-by: David Cunado <david.cunado@arm.com>
diff --git a/drivers/auth/mbedtls/mbedtls_common.c b/drivers/auth/mbedtls/mbedtls_common.c
index c71f81e..aad49a7 100644
--- a/drivers/auth/mbedtls/mbedtls_common.c
+++ b/drivers/auth/mbedtls/mbedtls_common.c
@@ -12,9 +12,9 @@
 /*
  * mbed TLS heap
  */
-#if (TBBR_KEY_ALG_ID == TBBR_ECDSA)
+#if (TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_ECDSA)
 #define MBEDTLS_HEAP_SIZE		(14*1024)
-#elif (TBBR_KEY_ALG_ID == TBBR_RSA)
+#elif (TF_MBEDTLS_KEY_ALG_ID == TF_MBEDTLS_RSA)
 #define MBEDTLS_HEAP_SIZE		(8*1024)
 #endif
 static unsigned char heap[MBEDTLS_HEAP_SIZE];