ASoC: atmel-pcm: split into two file

This patch is split original atmel-pcm.c into new atmel-pcm.c and
atmel-pcm-pdc.c two files. The new atmel-pcm.c is the share routine
while will be used for pdc or dma transfer.

Using SND_ATMEL_SOC_PDC to select using PDC for audio transfer

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/atmel/Kconfig

@@ -6,6 +6,10 @@ config SND_ATMEL_SOC
 	  the ATMEL SSC interface. You will also need
 	  to select the audio interfaces to support below.
 
+config SND_ATMEL_SOC_PDC
+	tristate
+	depends on SND_ATMEL_SOC
+
 config SND_ATMEL_SOC_SSC
 	tristate
 	depends on SND_ATMEL_SOC
@@ -17,6 +21,7 @@ config SND_ATMEL_SOC_SSC
 config SND_AT91_SOC_SAM9G20_WM8731
 	tristate "SoC Audio support for WM8731-based At91sam9g20 evaluation board"
 	depends on ATMEL_SSC && SND_ATMEL_SOC && AT91_PROGRAMMABLE_CLOCKS
+	select SND_ATMEL_SOC_PDC
 	select SND_ATMEL_SOC_SSC
 	select SND_SOC_WM8731
 	help

sound/soc/atmel/Makefile

@@ -1,8 +1,10 @@
 # AT91 Platform Support
 snd-soc-atmel-pcm-objs := atmel-pcm.o
+snd-soc-atmel-pcm-pdc-objs := atmel-pcm-pdc.o
 snd-soc-atmel_ssc_dai-objs := atmel_ssc_dai.o
 
 obj-$(CONFIG_SND_ATMEL_SOC) += snd-soc-atmel-pcm.o
+obj-$(CONFIG_SND_ATMEL_SOC_PDC) += snd-soc-atmel-pcm-pdc.o
 obj-$(CONFIG_SND_ATMEL_SOC_SSC) += snd-soc-atmel_ssc_dai.o
 
 # AT91 Machine Support