ramips: update ZBT WE1026 DTS-files

ramips: update ZBT WE1026 DTS-files

This commit makes the following changes to the WE1026 DTS-files:

* The parts that are unique to the -5G-version (LED and 5GHz wifi)
are moved to a separate file, so that WE1026.dtsi can be referenced also
by the DTS for the -H version.
* Use the generic "flash"-name for the spi-nor node.
* Add label MAC.

All changes have been tested on the WE1026-5G-16M and work fine. I.e.,
the device works as before the DTS-changes.

Signed-off-by: Kristian Evensen <[email protected]>
Acked-by: Mathias Kresin <[email protected]>
Acked-by: Alex Maclean <[email protected]>
Acked-by: INAGAKI Hiroshi <[email protected]>
Acked-by: Petr Štetiar <[email protected]>
[minor style fixes, rebased onto base-files split, remove obsolete
gpio-keys comment]
Signed-off-by: Adrian Schmutzler <[email protected]>