arm-bsp/trusted-firmware-a: fix the Corstone-500 system timer issue

This commit applies the TF-A fix allowing to use the right FPGA system
timer clock frequency for Corstone-500.

Change-Id: Iaa09d33eb76d9b2b74cb3400897c8cc0e3c694db
Signed-off-by: lakshmi Kailasanathan <lakshmi.Kailasanathan@arm.com>
Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
Signed-off-by: Ross Burton <ross.burton@arm.com>

meta-arm/recipes-bsp/trusted-firmware-a/files/0001-fdts-a5ds-Fix-for-the-system-timer-issue.patch

@@ -0,0 +1,34 @@
+Upstream-Status: Backport [e3c152d1156af8a4b6453376454ecdceaf81704c]
+Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+
+From e3c152d1156af8a4b6453376454ecdceaf81704c Mon Sep 17 00:00:00 2001
+From: lakshmi Kailasanathan <lakshmi.Kailasanathan@arm.com>
+Date: Fri, 17 Apr 2020 12:52:19 +0100
+Subject: [PATCH] fdts: a5ds: Fix for the system timer issue.
+
+A5DS FPGA system timer clock frequency is 7.5Mhz.
+The dt is file updated inline with the hardware
+clock frequency.
+
+Change-Id: I3f6c2e0d4a7b293175a42cf398a8730448504af9
+Signed-off-by: lakshmi Kailasanathan <lakshmi.Kailasanathan@arm.com>
+---
+ fdts/a5ds.dts | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/fdts/a5ds.dts b/fdts/a5ds.dts
+index 7334c4559..c6f5be6fa 100644
+--- a/fdts/a5ds.dts
++++ b/fdts/a5ds.dts
+@@ -128,7 +128,7 @@
+ 		#size-cells = <1>;
+ 		ranges;
+ 		reg = <0x1a040000 0x1000>;
+-		clock-frequency = <50000000>;
++		clock-frequency = <7500000>;
+ 
+ 		frame@1a050000 {
+ 			frame-number = <0>;
+-- 
+2.17.1
+

meta-arm/recipes-bsp/trusted-firmware-a/trusted-firmware-a_2.3.bb

@@ -12,6 +12,8 @@ SRCREV_tfa = "ecd27ad85f1eba29f6bf92c39dc002c85b07dad5"
 
 LIC_FILES_CHKSUM += "file://docs/license.rst;md5=189505435dbcdcc8caa63c46fe93fa89"
 
+SRC_URI += "file://0001-fdts-a5ds-Fix-for-the-system-timer-issue.patch"
+
 #
 # mbed TLS source
 # Those are used in trusted-firmware-a.inc if TFA_MBEDTLS is set to 1