drm_hwcomposer: Add Marissa and remove Haixia

Adding Marissa to OWNERS to get her listed on reviews.

While I'm in here, remove Haixia from OWNERS.

Change-Id: I6e07a686796c1d0cf3539be9bbdfc2b46dfb9938
Signed-off-by: Sean Paul <seanpaul@chromium.org>
diff --git a/OWNERS b/OWNERS
index 48122ec..4e41276 100644
--- a/OWNERS
+++ b/OWNERS
@@ -1,4 +1,4 @@
-hshi@chromium.org
 marcheu@chromium.org
+marissaw@google.com
 seanpaul@chromium.org
 zachr@chromium.org