[ALSA] Add SPI devices to ALSA Kconfig and Makefile

This patch adds SPI devices in the ALSA diretory, including the Kconfig and
Makefile.

Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
diff --git a/sound/Kconfig b/sound/Kconfig
index e48b9b3..b2a2db4 100644
--- a/sound/Kconfig
+++ b/sound/Kconfig
@@ -63,6 +63,10 @@
 
 source "sound/arm/Kconfig"
 
+if SPI
+source "sound/spi/Kconfig"
+endif
+
 source "sound/mips/Kconfig"
 
 source "sound/sh/Kconfig"