drm/i915/cnl: Add Cannonlake PCI IDs for Y-skus.

By the Spec all CNL Y skus are 2+2, i.e. GT2.

v2: Really include the PCI IDs to the picidlist[];

Reviewed-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1496781040-20888-4-git-send-email-rodrigo.vivi@intel.com