[ALSA] Add PC-speaker sound driver

Added PC-speaker sound driver (snd-pcsp).

Signed-off-by: Stas Sergeev <stsp@aknet.ru>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/drivers/Makefile b/sound/drivers/Makefile
index 8e55300..d4a07f9 100644
--- a/sound/drivers/Makefile
+++ b/sound/drivers/Makefile
@@ -20,4 +20,4 @@
 obj-$(CONFIG_SND_PORTMAN2X4) += snd-portman2x4.o
 obj-$(CONFIG_SND_ML403_AC97CR) += snd-ml403-ac97cr.o
 
-obj-$(CONFIG_SND) += opl3/ opl4/ mpu401/ vx/
+obj-$(CONFIG_SND) += opl3/ opl4/ mpu401/ vx/ pcsp/