ramips: Buffalo WZR-AGL300NH target support

I got work with this patch.
Ethernet switch (includes VLAN), WiFi connected via PCIe, LEDs, buttons.

In mtd partion map of DTS file, I renamed Linux firmware regions (kernel + root squashfs) to “firmware”because it allows kernel to split kernel and roots and rootfsdata.

signed-off-by:  <ngc@ff.iij4u.or.jp>
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SVN-Revision: 44470