ARM: kirkwood: Basic support for DNS-320 and DNS-325

Add support for the DNS-320 and DNS-325. Describe as much as currently possible
in the devicetree files, create a board-dnskw.c for everything else.

Changes since last submission (V3) [Addressing comments by]:-

* One MACH_DLINK_KIRKWOOD_DT for all dtb files [Grant Likely, Jason Cooper]
* Drop brain-dead select "select CONFIG_MTD_OF_PARTS" [Grant Likely]
* Don't add NAND support then throw it away immediately after [Grant Likely]
* Describe purpose of MPP 41, 42 & 49

Changes since last submission (V2):-

* Use IEEE-compliant "okay", rather than "ok" [Scott Wood]

Signed-off-by: Jamie Lentin <jm@lentin.co.uk>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
diff --git a/arch/arm/mach-kirkwood/Kconfig b/arch/arm/mach-kirkwood/Kconfig
index 90ceab7..636778e 100644
--- a/arch/arm/mach-kirkwood/Kconfig
+++ b/arch/arm/mach-kirkwood/Kconfig
@@ -58,6 +58,14 @@
 	  Say 'Y' here if you want your kernel to support the
 	  Marvell DreamPlug (Flattened Device Tree).
 
+config MACH_DLINK_KIRKWOOD_DT
+	bool "D-Link Kirkwood-based NAS (Flattened Device Tree)"
+	select ARCH_KIRKWOOD_DT
+	help
+	  Say 'Y' here if you want your kernel to support the
+	  Kirkwood-based D-Link NASes such as DNS-320 & DNS-325,
+	  using Flattened Device Tree.
+
 config MACH_TS219
 	bool "QNAP TS-110, TS-119, TS-119P+, TS-210, TS-219, TS-219P and TS-219P+ Turbo NAS"
 	help