On CTG+ read out the pipe bpp setting from hardware and fill it into
pipe config. Also check it appropriately.
v2: Don't do the pipe_bpp extraction inside the PCH only code block on
ILK+.
Avoid the PIPECONF read as we already have read it for the
PIPECONF_EANBLE check.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>