Revert "drm/i915: Avoid waking the engines just to check if they are idle"

Revert "drm/i915: Avoid waking the engines just to check if they are idle"

This reverts commit 0b702dca26580e3bbfbbaf22dfc29280b6263414.

CI reports that this is not as reliable as it first appears, with
failures starting to sporadically occur in selftests.

Fixes: 0b702dca2658 ("drm/i915: Avoid waking the engines just to check if they are idle")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190227204654.14907-1-chris@chris-wilson.co.uk