drm/xe: Add Wa_14015150844 for DG2 and Xe_LPG

drm/xe: Add Wa_14015150844 for DG2 and Xe_LPG

The workaround database tells us to set this bit, even though the bspec
indicates the bit doesn't exist on these platforms.  Since this is a
write-only register, we also can't read back its value to verify whether
it's actually working or not.  For now we'll trust that the workaround
database knows what it's talking about; if not, the hardware will just
ignore the attempt to write to a non-existent bit and it shouldn't cause
any problems.

Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com>
Link: https://lore.kernel.org/r/20230727220920.2291913-2-matthew.d.roper@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>