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: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index d73adf3..5de914a 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -220,6 +220,7 @@
 	select SUPPORT_SPL
 	select DM
 	select DM_SERIAL
+	select DM_SPI
 	select DM_GPIO
 	select DM_ETH