OWNERS: add Kirankumar Ballapalli

Propose myself (Kirankumar Ballapalli) as an additional maintainer.
I have contributed following patches to the webui-vue package.
[1] commits:
https://gerrit.openbmc.org/q/owner:kirankumarb%2540ami.com

Change-Id: Ifcb12a4bdb6b3365860fbe264c1b79bbf6d23a8a
Signed-off-by: Kirankumar Ballapalli <kirankumarb@ami.com>
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/OWNERS b/OWNERS
index c6527e7..8797e73 100644
--- a/OWNERS
+++ b/OWNERS
@@ -33,9 +33,9 @@
 
 owners:
 - gmills@linux.vnet.ibm.com
+- kirankumarb@ami.com
 
 reviewers:
-- kirankumarb@ami.com
 - a.nikhil@ibm.com
 
 matchers: