ASoC: atmel: fix build failure

m32r allmodconfig build is failing with the error:
ERROR: "bad_dma_ops" [sound/soc/atmel/snd-soc-atmel-pcm-pdc.ko] undefined!

The code is using DMA but the related dependency is not mentioned in the
Kconfig.
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/atmel/Kconfig

@@ -10,6 +10,7 @@ if SND_ATMEL_SOC
 
 config SND_ATMEL_SOC_PDC
 	tristate
+	depends on HAS_DMA
 	default m if SND_ATMEL_SOC_SSC_PDC=m && SND_ATMEL_SOC_SSC=m
 	default y if SND_ATMEL_SOC_SSC_PDC=y || (SND_ATMEL_SOC_SSC_PDC=m && SND_ATMEL_SOC_SSC=y)