docs: Release notes for v2.1.1

Add release notes for this v2.1.1 LTS release.

Signed-off-by: Nicola Mazzucato <nicola.mazzucato@arm.com>
Change-Id: I274786d4f6a47cb8d93a8343c3030abf6498206e
diff --git a/cmake/version.cmake b/cmake/version.cmake
index a5f5d23..44da4e7 100644
--- a/cmake/version.cmake
+++ b/cmake/version.cmake
@@ -6,7 +6,7 @@
 #-------------------------------------------------------------------------------
 
 # The 'TFM_VERSION_MANUAL' is used for fallback when Git tags are not available
-set(TFM_VERSION_MANUAL "2.1.0")
+set(TFM_VERSION_MANUAL "2.1.1")
 
 execute_process(COMMAND git describe --tags --always
     WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}