doc: Fix some broken links

Fix all external broken links reported by Sphinx linkcheck tool.

This does not take care of broken cross-references between internal
TF-A documentation files. These will be fixed in a future patch.

Change-Id: I2a740a3ec0b688c14aad575a6c2ac71e72ce051e
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
diff --git a/docs/perf/psci-performance-juno.rst b/docs/perf/psci-performance-juno.rst
index c127c1c..eab3e4d 100644
--- a/docs/perf/psci-performance-juno.rst
+++ b/docs/perf/psci-performance-juno.rst
@@ -286,7 +286,7 @@
 
 --------------
 
-*Copyright (c) 2019, Arm Limited and Contributors. All rights reserved.*
+*Copyright (c) 2019-2020, Arm Limited and Contributors. All rights reserved.*
 
-.. _Juno R1 platform: https://www.arm.com/files/pdf/Juno_r1_ARM_Dev_datasheet.pdf
+.. _Juno R1 platform: https://static.docs.arm.com/100122/0100/arm_versatile_express_juno_r1_development_platform_(v2m_juno_r1)_technical_reference_manual_100122_0100_05_en.pdf
 .. _TF master as of 31/01/2017: https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/?id=c38b36d