drm/xe: Ensure GT is in C0 during resumes

drm/xe: Ensure GT is in C0 during resumes

commit 95d0883ac8105717f59c2dcdc0d8b9150f13aa12 upstream.

This patch ensures the gt will be awake for the entire duration
of the resume sequences until GuCRC takes over and GT-C6 gets
re-enabled.

Before suspending GT-C6 is kept enabled, but upon resume, GuCRC
is not yet alive to properly control the exits and some cases of
instability and corruption related to GT-C6 can be observed.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4037
Suggested-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Xin Wang <x.wang@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4037
Link: https://lore.kernel.org/r/20250827000633.1369890-3-x.wang@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>