dma: dw: split driver to library part and platform code

To simplify the driver development let's split driver to library and platform
code parts. It helps us to add PCI driver in future.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[Fixed compile error and few checkpatch issues]
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/Makefile

@@ -15,7 +15,7 @@ obj-$(CONFIG_FSL_DMA) += fsldma.o
 obj-$(CONFIG_MPC512X_DMA) += mpc512x_dma.o
 obj-$(CONFIG_PPC_BESTCOMM) += bestcomm/
 obj-$(CONFIG_MV_XOR) += mv_xor.o
-obj-$(CONFIG_DW_DMAC) += dw/
+obj-$(CONFIG_DW_DMAC_CORE) += dw/
 obj-$(CONFIG_AT_HDMAC) += at_hdmac.o
 obj-$(CONFIG_MX3_IPU) += ipu/
 obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o

drivers/dma/dw/Kconfig

@@ -2,10 +2,14 @@
 # DMA engine configuration for dw
 #
 
-config DW_DMAC
+config DW_DMAC_CORE
 	tristate "Synopsys DesignWare AHB DMA support"
 	depends on GENERIC_HARDIRQS
 	select DMA_ENGINE
+
+config DW_DMAC
+	tristate "Synopsys DesignWare AHB DMA platform driver"
+	select DW_DMAC_CORE
 	default y if CPU_AT32AP7000
 	help
 	  Support the Synopsys DesignWare AHB DMA controller. This
@@ -14,7 +18,7 @@ config DW_DMAC
 config DW_DMAC_BIG_ENDIAN_IO
 	bool "Use big endian I/O register access"
 	default y if AVR32
-	depends on DW_DMAC
+	depends on DW_DMAC_CORE
 	help
 	  Say yes here to use big endian I/O access when reading and writing
 	  to the DMA controller registers. This is needed on some platforms,

drivers/dma/dw/Makefile

@@ -1 +1,5 @@
-obj-$(CONFIG_DW_DMAC) += dw_dmac.o
+obj-$(CONFIG_DW_DMAC_CORE)	+= dw_dmac_core.o
+dw_dmac_core-objs	:= core.o
+
+obj-$(CONFIG_DW_DMAC)		+= dw_dmac.o
+dw_dmac-objs		:= platform.o