OWNERS: switch 'matches' to 'matchers'

The original OWNERS template had a mistake which used 'matches' instead
of the field supported by the Gerrit plugin 'matchers'.  Update the
OWNERS file to have the correct field.

Signed-off-by: Thang Q. Nguyen <thang@os.amperecomputing.com>
Change-Id: Ibaae9d9c6cf51b3713d63093b7715cbe34531b8c
diff --git a/OWNERS b/OWNERS
index fd885e7..0f4a96a 100644
--- a/OWNERS
+++ b/OWNERS
@@ -20,7 +20,7 @@
 #   * reviewers: A list of individuals who have requested review notification
 #     on the repository.
 #
-#   * matches: A list of specific file/path matches for granular 'owners' and
+#   * matchers: A list of specific file/path matchers for granular 'owners' and
 #     'reviewers'.  See 'owners' plugin documentation.
 #
 #   * openbmc: A list of openbmc-specific meta-data about owners and reviewers.
@@ -39,7 +39,7 @@
 - pvo@amperecomputing.com
 - qnguyen@amperecomputing.com
 
-matches:
+matchers:
 
 openbmc:
 - name: Chuong Tran