at91: taurus: Enable DM_SPI

Enable DM_SPI for atmel SPI driver on taurus board.

Kept few functions related to non-dm and gpio on board
files for reference and will be remove once code moved
to relevant drivers.

Cc: Heiko Schocher <hs@denx.de>
Signed-off-by: NJagan Teki <jagan@amarulasolutions.com>

arch/arm/mach-at91/Kconfig

@@ -220,6 +220,7 @@ config TARGET_TAURUS
 	select SUPPORT_SPL
 	select DM
 	select DM_SERIAL
+	select DM_SPI
 	select DM_GPIO
 	select DM_ETH
 

board/siemens/taurus/taurus.c

@@ -283,6 +283,8 @@ int board_early_init_f(void)
 	return 0;
 }
 
+/* FIXME gpio code here need to handle through DM_GPIO */
+#ifndef CONFIG_DM_SPI
 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
 {
 	return bus == 0 && cs == 0;
@@ -297,6 +299,7 @@ void spi_cs_deactivate(struct spi_slave *slave)
 {
 	at91_set_gpio_value(TAURUS_SPI_CS_PIN, 1);
 }
+#endif
 
 #ifdef CONFIG_USB_GADGET_AT91
 #include <linux/usb/at91_udc.h>