go7007 - Add missing dependency on sound subsystem

The dependency on the sound system is missing for go7007 driver, which
resulted in missing symbols like
  drivers/built-in.o: In function `go7007_snd_remove':
  : undefined reference to `snd_card_disconnect'
  drivers/built-in.o: In function `go7007_snd_remove':
  : undefined reference to `snd_card_free_when_closed'
  ...

This patch adds the dependency on CONFIG_SND, and selects CONFIG_SND_PCM
properly.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Ross Cohen <rcohen@snurgle.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/go7007/Kconfig

 config VIDEO_GO7007
 	tristate "Go 7007 support"
 	depends on VIDEO_DEV && PCI && I2C && INPUT
+	depends on SND
 	select VIDEOBUF_DMA_SG
 	select VIDEO_IR
 	select VIDEO_TUNER
 	select VIDEO_TVEEPROM
+	select SND_PCM
 	select CRC32
 	default N
 	---help---