doc: RAS: fixing broken links

There were some links in the file "ras.rst" which were broken, this
patch fixes all the broken links in this file.

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I00cf080e9338af5786239a4843cb4c2e0cc9d99d
diff --git a/docs/design/interrupt-framework-design.rst b/docs/design/interrupt-framework-design.rst
index 14f7227..2e200aa 100644
--- a/docs/design/interrupt-framework-design.rst
+++ b/docs/design/interrupt-framework-design.rst
@@ -138,6 +138,8 @@
    reason to route the interrupt to EL3 software and then hand it back to
    non-secure software for handling.
 
+.. _EL3 interrupts:
+
 EL3 interrupts
 ^^^^^^^^^^^^^^