Add OWNERS in system/libhidl

Owners are selected from top CL approvals or owners.
They will be suggested to review/approve future CLs.

Test: build/make/tools/checkowners.py -c -v OWNERS
Change-Id: Ie745317e52ddb268b5cf64f042055ddcfb838369
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..3631423
--- /dev/null
+++ b/OWNERS
@@ -0,0 +1,5 @@
+smoreland@google.com
+elsk@google.com
+maco@google.com
+hridya@google.com
+malchev@google.com