spi:Add Freescale DSPI driver for Vybrid VF610 platform

The serial peripheral interface (SPI) module implemented on Freescale Vybrid
platform provides a synchronous serial bus for communication between Vybrid
and the external peripheral device.
The SPI supports full-duplex, three-wire synchronous transfer, has TX/RX FIFO
with depth of four entries.

This driver is the SPI master mode driver and has been tested on Vybrid
VF610TWR board.
Signed-off-by: Alison Wang <b18965@freescale.com>
Signed-off-by: Chao Fu  <b44548@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/Kconfig

@@ -248,6 +248,13 @@ config SPI_FSL_SPI
 	  This also enables using the Aeroflex Gaisler GRLIB SPI controller in
 	  master mode.
 
+config SPI_FSL_DSPI
+	tristate "Freescale DSPI controller"
+	select SPI_BITBANG
+	help
+	  This enables support for the Freescale DSPI controller in master
+	  mode. VF610 platform uses the controller.
+
 config SPI_FSL_ESPI
 	bool "Freescale eSPI controller"
 	depends on FSL_SOC

drivers/spi/Makefile

@@ -30,6 +30,7 @@ spi-dw-midpci-objs			:= spi-dw-pci.o spi-dw-mid.o
 obj-$(CONFIG_SPI_EP93XX)		+= spi-ep93xx.o
 obj-$(CONFIG_SPI_FALCON)		+= spi-falcon.o
 obj-$(CONFIG_SPI_FSL_CPM)		+= spi-fsl-cpm.o
+obj-$(CONFIG_SPI_FSL_DSPI)		+= spi-fsl-dspi.o
 obj-$(CONFIG_SPI_FSL_LIB)		+= spi-fsl-lib.o
 obj-$(CONFIG_SPI_FSL_ESPI)		+= spi-fsl-espi.o
 obj-$(CONFIG_SPI_FSL_SPI)		+= spi-fsl-spi.o