drm/i915/xehp: Create separate reg definitions for new MCR registers

Starting in Xe_HP, several registers our driver works with have been
converted from singleton registers into replicated registers with
multicast behavior.  Although the registers are still located at the
same MMIO offsets as on previous platforms, let's duplicate the register
definitions in preparation for upcoming patches that will handle
multicast registers in a special manner.

The registers that are now replicated on Xe_HP are:
 * PAT_INDEX (mslice replication)
 * FF_MODE2 (gslice replication)
 * COMMON_SLICE_CHICKEN3 (gslice replication)
 * SLICE_COMMON_ECO_CHICKEN1 (gslice replication)
 * SLICE_UNIT_LEVEL_CLKGATE (gslice replication)
 * LNCFCMOCS (lncf replication)

Note that there are a couple places in selftest_mocs.c where the
gen9 version of LNCFCMOCS is still used without regards for which
platform we're on.  Those cases are just doing an offset lookup and not
issuing any CPU reads/writes of the register, so the potentially
multicast nature of the register doesn't come into play.

v2:
 - Add commit message note about the unconditional GEN9_LNCFCMOCS usage
   in selftest_mocs.  (Bala)
 - Include some additional TLB registers.

Bspec: 66534
Cc: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221014230239.1023689-3-matthew.d.roper@intel.com