drm/i915/DMC/KBL: Load DMC on KBL using the no_stepping_info array

Currently, for display there is only one DMC image for KBL.
Remove the stepping_info table for KBL and use the no_stepping_info
array for loading the firmware.

v2: Removed the block of code as pointed out by Rodrigo to make the
loads as generic as possible.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477355301-7035-1-git-send-email-anusha.srivatsa@intel.com