Update version for v2.3.0-rc3 release

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/VERSION b/VERSION
index 0a58e8e..b1a306a 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.2.92
+2.2.93