drm/i915/dg1: Fix power gate sequence.

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: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13381
Fixes: 85a12d7eb8fe ("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>