drm/i915/active: remove useless i915_utils.h include

Not needed.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/52b1cf56c16bf669a1357ce81d9232c5480914a4.1639142167.git.jani.nikula@intel.com