DSC 1.2 is supported from MTL, hence program ICH accordingly.

Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: NVandita Kulkarni <vandita.kulkarni@intel.com>
Reviewed-by: NAnkit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220817124516.284456-2-jani.nikula@intel.com