rcar-gen3: optee-client: WORKAROUND to build with GCC 8.x

This commit applies a W/A patch from optee upstream to fix
GCC 8 format-truncation errors.

[1] OP-TEE/optee_client#126

Signed-off-by: Thuy Tran <thuy.tran.xh@renesas.com>
Signed-off-by: Khang Nguyen <khang.nguyen.xw@renesas.com>
Signed-off-by: Takamitsu Honda <takamitsu.honda.pv@renesas.com>

meta-rcar-gen3/recipes-bsp/optee/optee-client/0001-Fix-for-teec_trace.c-snprintf-Werror-format-truncati.patch

@@ -0,0 +1,28 @@
+From 30dd2986fb64aba7ee78d4e231c344e2c39d7999 Mon Sep 17 00:00:00 2001
+From: Simon Hughes <simon.hughes@arm.com>
+Date: Thu, 21 Jun 2018 17:22:23 +0100
+Subject: [PATCH] Fix for teec_trace.c snprintf -Werror=format-truncation=
+ error.
+
+Signed-off-by: Simon Hughes <simon.hughes@arm.com>
+---
+ libteec/src/teec_trace.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/libteec/src/teec_trace.c b/libteec/src/teec_trace.c
+index 78b79d6..c91bc43 100644
+--- a/libteec/src/teec_trace.c
++++ b/libteec/src/teec_trace.c
+@@ -106,7 +106,8 @@ int _dprintf(const char *function, int flen, int line, int level,
+ 		 */
+ 		int thread_id = syscall(SYS_gettid);	/* perf issue ? */
+
+-		snprintf(prefixed, MAX_PRINT_SIZE,
++		int len = 0;
++		len  = snprintf(prefixed+len, MAX_PRINT_SIZE,
+ 			 "%s [%d] %s:%s:%d: %s",
+ 			 trace_level_strings[level], thread_id, prefix, func,
+ 			 line, raw);
+-- 
+2.7.4
+

meta-rcar-gen3/recipes-bsp/optee/optee-client_git.bb

@@ -10,6 +10,7 @@ SRCREV = "3f16662284a69fdec97b1712064be94d1fed7ae7"
 
 SRC_URI += " \
     file://optee.service \
+    file://0001-Fix-for-teec_trace.c-snprintf-Werror-format-truncati.patch \
 "
 
 inherit pythonnative systemd