Doc: Removed TF-M prefix from document heading

This patch removes the TF-M/Trusted Firmware prefix from the
title heading across the documentation.

Change-Id: I60e0c6e48615f67ee040a0d6dbc7d6f1873856e7
Signed-off-by: Galanakis, Minos <minos.galanakis@arm.com>
diff --git a/docs/user_guides/tfm_integration_guide.rst b/docs/user_guides/tfm_integration_guide.rst
index df8a87a..7db65a0 100644
--- a/docs/user_guides/tfm_integration_guide.rst
+++ b/docs/user_guides/tfm_integration_guide.rst
@@ -1,6 +1,6 @@
-######################
-TF-M integration guide
-######################
+#################
+Integration guide
+#################
 The purpose of this document is to provide a guide on how to integrate TF-M
 with other hardware platforms and operating systems.