Doc: Update link to TBBR-CLIENT specification

Change-Id: Iafa79b6f7891d3eebec9908a8f7725131202beb3
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
diff --git a/readme.rst b/readme.rst
index 998369f..fc03555 100644
--- a/readme.rst
+++ b/readme.rst
@@ -12,7 +12,7 @@
 such as:
 
 -  The `Power State Coordination Interface (PSCI)`_
--  Trusted Board Boot Requirements (TBBR, Arm DEN0006C-1)
+-  `Trusted Board Boot Requirements CLIENT (TBBR-CLIENT)`_
 -  `SMC Calling Convention`_
 -  `System Control and Management Interface (SCMI)`_
 -  `Software Delegated Exception Interface (SDEI)`_
@@ -320,6 +320,7 @@
 .. _Secure Monitor: http://www.arm.com/products/processors/technologies/trustzone/tee-smc.php
 .. _Power State Coordination Interface (PSCI): PSCI_
 .. _PSCI: http://infocenter.arm.com/help/topic/com.arm.doc.den0022d/Power_State_Coordination_Interface_PDD_v1_1_DEN0022D.pdf
+.. _Trusted Board Boot Requirements CLIENT (TBBR-CLIENT): https://developer.arm.com/docs/den0006/latest/trusted-board-boot-requirements-client-tbbr-client-armv8-a
 .. _SMC Calling Convention: http://infocenter.arm.com/help/topic/com.arm.doc.den0028b/ARM_DEN0028B_SMC_Calling_Convention.pdf
 .. _System Control and Management Interface (SCMI): SCMI_
 .. _SCMI: http://infocenter.arm.com/help/topic/com.arm.doc.den0056a/DEN0056A_System_Control_and_Management_Interface.pdf