drm/i915/dg2: Add support for new DG2-G12 revid 0x1

The bspec has been updated with a new revision 0x1 that
translates to A1 GT stepping and C0 display stepping.

Bspec: 44477

Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230829135945.1201574-1-swati2.sharma@intel.com