Update Doxygen project number for 22.05 patch release

Signed-off-by: Nikhil Raj <nikhil.raj@arm.com>
Change-Id: If22b8fb0013c70fe228fdba446e34962ae5fc421
diff --git a/docs/Doxyfile b/docs/Doxyfile
index bfa10dd..65cb404 100644
--- a/docs/Doxyfile
+++ b/docs/Doxyfile
@@ -61,7 +61,7 @@
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 22.05
+PROJECT_NUMBER         = 22.05.01
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a