release: Zephyr 2.2.0-rc3

Bumped to v2.2.0-rc3

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/VERSION b/VERSION
index db5945c..d6d7477 100644
--- a/VERSION
+++ b/VERSION
@@ -2,4 +2,4 @@
 VERSION_MINOR = 2
 PATCHLEVEL = 0
 VERSION_TWEAK = 0
-EXTRAVERSION = rc2
+EXTRAVERSION = rc3