doc: Use proper note and warning annotations

The documentation contains plenty of notes and warnings. Enable
special rendering of these blocks by converting the note prefix
into a .. note:: annotation.

Change-Id: I34e26ca6bf313d335672ab6c2645741900338822
Signed-off-by: Paul Beesley <paul.beesley@arm.com>
diff --git a/docs/design/interrupt-framework-design.rst b/docs/design/interrupt-framework-design.rst
index b19f7f7..f68cf21 100644
--- a/docs/design/interrupt-framework-design.rst
+++ b/docs/design/interrupt-framework-design.rst
@@ -416,8 +416,9 @@
 Test secure payload dispatcher behavior
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-**Note:** where this document discusses ``TSP_NS_INTR_ASYNC_PREEMPT`` as being
-``1``, the same results also apply when ``EL3_EXCEPTION_HANDLING`` is ``1``.
+.. note::
+   Where this document discusses ``TSP_NS_INTR_ASYNC_PREEMPT`` as being
+   ``1``, the same results also apply when ``EL3_EXCEPTION_HANDLING`` is ``1``.
 
 The TSPD only handles Secure-EL1 interrupts and is provided with the following
 routing model at build time.