drm/i915: add platform tag to WA

v2: add more missing platform tags
v3: change tag to cnp rather than using gen9,gen10

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171205190118.7088-2-lucas.demarchi@intel.com