Revert "DispSync: workaround HH hardware vsync issue"

This reverts commit c734d95c575830ffc97fc5d2ae14b020c95d05de, which was
a workaround for a bug on a device which is now obsolete.

Bug: 25845510
Change-Id: I3244bfd3f758c52dfe76e9d5b0a72bbcffdf5a6f
2 files changed