Refactor transitions by templatizing to have default behavior for most cases
and full specializations for specific cases.
Partial specialization of functions is not allowed, so create templatized
intermediate functions for those use cases.
For ex: if we have 8 states, we don't need 8x8 transition handlers.
Add and define OV_DUAL_DISPLAY state.
Add a GenericPipe for subtitles to OV_2D_VIDEO_ON_PANEL_TV state.
Add a 2D_VIDEO_ON_TV state and its transitions.
Change-Id: I53b017b9a41db5894c263ccb446b7ec8875ef3aa
446b936947