trusty: Require dynamic translation tables

Trusty requires dynamic translation tables support, so the makefile of
Trusty itself should request it. Not doing so causes platforms such as
FVP to fail to build with Trusty. Other platforms like Tegra still build
because they use dynamic translation tables by default.

Change-Id: Id67d3b9e1f7d0547fa81e81cefa3faf1e0e6f876
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

services/spd/trusty/trusty.mk

 #
-# Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -13,6 +13,8 @@ ifeq (${TRUSTY_SPD_WITH_GENERIC_SERVICES},1)
 SPD_SOURCES		+=	services/spd/trusty/generic-arm64-smcall.c
 endif
 
+BL31_CFLAGS	+=		-DPLAT_XLAT_TABLES_DYNAMIC=1
+
 NEED_BL32		:=	yes
 
 CTX_INCLUDE_FPREGS	:=	1