ata: sata_dwc_460ex: select only core part of DMA driver

There is no need to have a platform driver compiled since the DMA driver is
used as a library.
Tested-by: NChristian Lamparter <chunkeey@googlemail.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

drivers/ata/Kconfig

@@ -306,7 +306,7 @@ config ATA_PIIX
 config SATA_DWC
 	tristate "DesignWare Cores SATA support"
 	depends on 460EX
-	select DW_DMAC
+	select DW_DMAC_CORE
 	help
 	  This option enables support for the on-chip SATA controller of the
 	  AppliedMicro processor 460EX.