drm/i915/adl-n: Add stepping info

Add ADL-N stepping-substepping info in
accordance to BSpec.

Bspec: 68397

Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220303113252.212873-1-tejaskumarx.surendrakumar.upadhyay@intel.com