drm/i915/display: Include i915_active header in frontbuffer tracking code

Intel frontbuffer tracking code is using i915_active functions -> include
i915_active.h directly instead of relying getting indirectly included.

Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230929112047.1151914-1-jouni.hogander@intel.com

drivers/gpu/drm/i915/display/intel_frontbuffer.c

@@ -56,6 +56,7 @@
  */
 
 #include "gem/i915_gem_object_frontbuffer.h"
+#include "i915_active.h"
 #include "i915_drv.h"
 #include "intel_display_trace.h"
 #include "intel_display_types.h"