drm/i915: acpi/video.c fix section mismatch warning

Currently acpi_video_exit() is exported as well as using __exit which causes:

  WARNING: drivers/acpi/video.o(__ksymtab+0x0): Section mismatch in reference from the variable __ksymtab_acpi_video_exit to the function .exit.text:acpi_video_exit()
  The symbol acpi_video_exit is exported and annotated __exit
  Fix this by removing the __exit annotation of acpi_video_exit or drop the export.
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

drivers/acpi/video.c

@@ -2334,7 +2334,7 @@ static int __init acpi_video_init(void)
 	return acpi_video_register();
 }
 
-void __exit acpi_video_exit(void)
+void acpi_video_exit(void)
 {
 
 	acpi_bus_unregister_driver(&acpi_video_bus);