ARM: cns3xxx: enable multiplatform support

This moves the cns3xxx configuration option inside of ARCH_MULTIPLATFORM,
since there is no reason for not doing it now. We can then also remove
the three header files that become obsolete.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/arm/configs/cns3420vb_defconfig b/arch/arm/configs/cns3420vb_defconfig
index b79e984..b1ff5cd 100644
--- a/arch/arm/configs/cns3420vb_defconfig
+++ b/arch/arm/configs/cns3420vb_defconfig
@@ -19,6 +19,8 @@
 CONFIG_MODVERSIONS=y
 # CONFIG_BLK_DEV_BSG is not set
 CONFIG_IOSCHED_CFQ=m
+CONFIG_ARCH_MULTI_V6=y
+#CONFIG_ARCH_MULTI_V7 is not set
 CONFIG_ARCH_CNS3XXX=y
 CONFIG_MACH_CNS3420VB=y
 CONFIG_DEBUG_CNS3XXX=y