platform/x86: int3472/discrete: add LEDS_CLASS dependency

int3472 now fails to link when the LED support is disabled:

x86_64-linux-ld: drivers/platform/x86/intel/int3472/led.o: in function `skl_int3472_register_pled':
led.c:(.text+0xf4): undefined reference to `led_classdev_register_ext'
x86_64-linux-ld: led.c:(.text+0x131): undefined reference to `led_add_lookup'
x86_64-linux-ld: drivers/platform/x86/intel/int3472/led.o: in function `skl_int3472_unregister_pled':
led.c:(.text+0x16b): undefined reference to `led_remove_lookup'
x86_64-linux-ld: led.c:(.text+0x177): undefined reference to `led_classdev_unregister'

Add an explicit Kconfig dependency.

Fixes: 5ae20a8050d0 ("platform/x86: int3472/discrete: Create a LED class device for the privacy LED")
Signed-off-by: Arnd Bergmann <[e-mail]>
Reviewed-by: Sakari Ailus <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Hans de Goede <[e-mail]>
Signed-off-by: Hans de Goede <[e-mail]>

drivers/platform/x86/intel/int3472/Kconfig

···
 	depends on COMMON_CLK
 	depends on I2C
 	depends on GPIOLIB
+	depends on LEDS_CLASS
 	depends on REGULATOR
 	select MFD_CORE
 	select REGMAP_I2C