drm/i915/guc: Remove sample_forcewake h2g action

This action is no-op in the GuC side for a few versions already
and it is getting entirely removed soon, in an upcoming version.

Time to remove before we face communication issues.

Cc: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210603051630.2635-5-matthew.brost@intel.com