[ALSA] pcsp - Fix dependency in Kconfig

Added the proper dependency to Kconfig for snd-pcsp driver.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/drivers/Kconfig b/sound/drivers/Kconfig
index 78648c4..fe85af1 100644
--- a/sound/drivers/Kconfig
+++ b/sound/drivers/Kconfig
@@ -7,6 +7,7 @@
 config SND_PCSP
 	tristate "Internal PC speaker support"
 	depends on X86_PC && HIGH_RES_TIMERS
+	depends on INPUT
 	help
 	  If you don't have a sound card in your computer, you can include a
 	  driver for the PC speaker which allows it to act like a primitive