drm/i915/gen12: Update shadowed register table

The bspec lists many shadowed registers (i.e., registers for which we
don't need to grab forcewake when writing) that we weren't tracking in
the driver.  Although we may not actually use all of these registers
right now, it's best to just match the bspec list exactly.

Note that the bspec also lists registers that are shadowed for various
HW-internal accesses; we can ignore those and just list the ones that
are shadowed for accesses from the IA/CPU.

Bspec: 52077
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Caz Yokoyama <caz.yokoyama@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210729054118.2458523-6-matthew.d.roper@intel.com