Disable workaround for CVE-2017-5715 on unaffected platforms

Change-Id: Ib67b841ab621ca1ace3280e44cf3e1d83052cb73
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>
diff --git a/plat/xilinx/zynqmp/platform.mk b/plat/xilinx/zynqmp/platform.mk
index bdd194b..bddf305 100644
--- a/plat/xilinx/zynqmp/platform.mk
+++ b/plat/xilinx/zynqmp/platform.mk
@@ -14,6 +14,8 @@
 # Do not enable SVE
 ENABLE_SVE_FOR_NS	:= 0
 
+WORKAROUND_CVE_2017_5715	:=	0
+
 ifdef ZYNQMP_ATF_MEM_BASE
     $(eval $(call add_define,ZYNQMP_ATF_MEM_BASE))