Update release version in Doxygen

Signed-off-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Change-Id: I812bcb68b7c91ec65855835a8aa25e2a5aed45af
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/2826
Tested-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
diff --git a/docs/Doxyfile b/docs/Doxyfile
index 9a1eb17..f959a4a 100644
--- a/docs/Doxyfile
+++ b/docs/Doxyfile
@@ -38,7 +38,7 @@
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 20.02
+PROJECT_NUMBER         = 20.02.1
 
 # 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