samsung-laptop: fix config build error

Fix build failure when ACPI_VIDEO=m and SAMSUNG_LAPTOP=y.
The patch prevents that specific config combination.

drivers/built-in.o: In function `samsung_init':
samsung-laptop.c:(.init.text+0x128ff): undefined reference to `acpi_video_unregister'

Signed-off-by: Randy Dunlap <[e-mail]>
Reported-by: Randy Dunlap <[e-mail]>
Reported-by: Fengguang Wu <[e-mail]>
Cc: Corentin Chary <[e-mail]>

build testing:
ACPI_VIDEO=m, SAMSUNG_LAPTOP=m: OK
ACPI_VIDEO=y, SAMSUNG_LAPTOP=m: OK
ACPI_VIDEO=y, SAMSUNG_LAPTOP=y: OK
ACPI=n, SAMSUNG_LAPTOP=y: OK
ACPI=n, SAMSUNG_LAPTOP=m: OK
Signed-off-by: Matthew Garrett <[e-mail]>

drivers/platform/x86/Kconfig

···
 	tristate "Samsung Laptop driver"
 	depends on X86
 	depends on RFKILL || RFKILL = n
+	depends on ACPI_VIDEO || ACPI_VIDEO = n
 	depends on BACKLIGHT_CLASS_DEVICE
 	select LEDS_CLASS
 	select NEW_LEDS