Input: leds - change config symbol dependency for audio mute trigger

In a follow-up patch implementation of the LED audio trigger will be
moved to sound/core/snd_ctl_led, including removal of config symbol
LEDS_AUDIO_TRIGGER. Also as of today the audio mute LED trigger
is effectively a no-op w/o config symbol SND_CTL_LED being defined.
Therefore switch the dependency to this config symbol.

Suggested-by: Dmitry Torokhov <[e-mail]>
Signed-off-by: Heiner Kallweit <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/input-leds.c

···
 #define VT_TRIGGER(_name)	.trigger = NULL
 #endif
 
-#if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
+#if IS_ENABLED(CONFIG_SND_CTL_LED)
 #define AUDIO_TRIGGER(_name)	.trigger = _name
 #else
 #define AUDIO_TRIGGER(_name)	.trigger = NULL