OWNERS: add geissonator as maintainer

The service-config-manager repository has mostly been in maintenance
mode and there has been a bit of a struggle getting general
maintenance commits through.

I plan on doing some work within this repository and have been reviewing
it for a while now. I would be happy to assist with review and merges in
this repository.

Change-Id: I417984a8adccc377ee77433654ac1ced8642e676
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
diff --git a/OWNERS b/OWNERS
index 6e5545a..9d1e39b 100644
--- a/OWNERS
+++ b/OWNERS
@@ -33,9 +33,9 @@
 
 owners:
 - apparao.puli@linux.intel.com
+- geissonator@yahoo.com
 
 reviewers:
-- geissonator@yahoo.com
 
 matchers: