am335x: baltos: Enable DM_SPI

Enable DM_SPI for am355x baltos board.

Build is fine, but not tested.

Cc: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Yegor Yefremov <yegorslists@googlemail.com>
diff --git a/configs/am335x_baltos_defconfig b/configs/am335x_baltos_defconfig
index 2781d49..c92e0cc 100644
--- a/configs/am335x_baltos_defconfig
+++ b/configs/am335x_baltos_defconfig
@@ -60,6 +60,7 @@
 CONFIG_MII=y
 CONFIG_DRIVER_TI_CPSW=y
 CONFIG_SPI=y
+CONFIG_DM_SPI=y
 CONFIG_OMAP3_SPI=y
 CONFIG_USB=y
 CONFIG_DM_USB=y