drm/i915/dsi/xelpd: Add DSI transcoder support

Update ADL_P device info to support DSI0, DSI1

v2: Re-define cpu_transcoder_mask only (Jani)

Signed-off-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211019151435.20477-3-vandita.kulkarni@intel.com