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
1 file changed