board: ge: bx50v3: Enable CONFIG_DM_SPI, CONFIG_DM_SPI_FLASH

Use SPI flash device model, and remove SPI pin configuration code since
the pinctrl driver is used.

Signed-off-by: Ian Ray <ian.ray@ge.com>
diff --git a/configs/ge_bx50v3_defconfig b/configs/ge_bx50v3_defconfig
index 1acda9e..14114ac 100644
--- a/configs/ge_bx50v3_defconfig
+++ b/configs/ge_bx50v3_defconfig
@@ -59,3 +59,5 @@
 CONFIG_PINCTRL=y
 CONFIG_PINCTRL_IMX6=y
 CONFIG_DM_GPIO=y
+CONFIG_DM_SPI=y
+CONFIG_DM_SPI_FLASH=y