cutf_cvm hwcomposer device stub

This is the cutf_cvm hwcomposer implementation with most
functionality stubbed out. The common functionality between cutf_cvm
and cutf_ivsh is the vsync thread, which can't be stubbed out due to
test failures.

Bug: 122976892
Change-Id: I5b6b5a8f9135cac421f37937d67875180aadf6af