While old platforms had 3 transcoders and 3 pipes (1:1), HSW has
4 transcoders and 3 pipes.
These regs were being used only by HDMI code where pipe is always the same
thing as cpu_transcoder.
This patch allow us to use them for DP, specially for TRANSCODER_EDP.

v2: Adding HSW_TVIDEO_DIP_VSC_DATA to transmit vsc to eDP.
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>