drm/i915: Move i915_gem_restore_fences to i915_gem_resume

drm/i915: Move i915_gem_restore_fences to i915_gem_resume

i915_gem_restore_fences is GEM resumption task hence it is moved to
i915_gem_resume from i915_restore_state.

Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1506661116-12106-1-git-send-email-sagar.a.kamble@intel.com
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>