drm/i915/dg1: Fix power gate sequence.

sub-pipe PG is not present on DG1. Setting these bits can disable
other power gates and cause GPU hangs on video playbacks.

VLK: 16314, 4304

Closes: #13381


Fixes: 85a12d7e ("drm/i915/tgl: Fix Media power gate sequence.")
Cc: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241219210019.70532-1-rodrigo.vivi@intel.com


Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
(cherry picked from commit de706194)
Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>