ARM: vf610: move to standard arch/board approach

Move Freescale/NXP Vybrid to a standard arch/board approach, similar
to what has been done to i.MX 6 earlier in commit 89ebc82137be ("ARM:
mx6: move to a standard arch/board approach").

Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
diff --git a/configs/vf610twr_nand_defconfig b/configs/vf610twr_nand_defconfig
index c78f716..a313910 100644
--- a/configs/vf610twr_nand_defconfig
+++ b/configs/vf610twr_nand_defconfig
@@ -1,4 +1,5 @@
 CONFIG_ARM=y
+CONFIG_ARCH_VF610=y
 CONFIG_TARGET_VF610TWR=y
 CONFIG_DEFAULT_DEVICE_TREE="vf610-twr"
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=board/freescale/vf610twr/imximage.cfg,ENV_IS_IN_NAND"