ACPI / video: fix ACPI_VIDEO dependencies

ACPI_VIDEO stopped depending on VIDEO_OUTPUT_CONTROL over 3 years ago
(see commit 677bd810, "ACPI video: remove output switching control".)
So it's about time to remove the Kconfig dependency between these two
options.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>