arch/Config.in.nds32: force syntax colouring to kconfig

It is too sad when an editor picks up the wrong syntax...

Like was done in e837837791 for all the other archs, force
syntax to kconfig for nds32 too.

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Nylon Chen <nylon7@andestech.com>
Reviewed-by:Nylon Chen <nylon7@andestech.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

arch/Config.in.nds32

@@ -9,3 +9,6 @@ config BR2_ENDIAN
 
 config BR2_READELF_ARCH_NAME
 	default "Andes Technology compact code size embedded RISC processor family"
+
+# vim: ft=kconfig
+# -*- mode:kconfig; -*-