sound: Fix make allmodconfig on MIPS

The compile of soundcard.c is broken on MIPS when allmodconfig is used
because of the missing MAX_DMA_CHANNELS definition.  As a simple
workaround, just add a Kconfig dependency.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/oss/Kconfig

@@ -250,6 +250,7 @@ config MSND_FIFOSIZE
 menuconfig SOUND_OSS
 	tristate "OSS sound modules"
 	depends on ISA_DMA_API && VIRT_TO_BUS
+	depends on !ISA_DMA_SUPPORT_BROKEN
 	help
 	  OSS is the Open Sound System suite of sound card drivers.  They make
 	  sound programming easier since they provide a common API.  Say Y or