[FS#409] Archer C7 all leds are green

[LEDE Bugs]

The following task has a new comment added:

FS#409 - Archer C7 all leds are green
User who did this - howl (howl)

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Let me copy your commit comment for better understanding (I used code block because can't find quote at least in the icons above):

Revert "ar71xx: fix Archer C7 LED colour names"

This reverts commit e79ecb4c26471526552d2473bb50d331c3dafb87.

The commit was incomplete and the issue that should be fixed isn't
that easy fixable. The Archer C7 mach file is used for the Archer C5,
WDR4900 and WDR7500 as well. Where the WDRs in compare to the Archer
do have blue LEDs.

I see, I didn't think about it despite I know the WDR7500. I didn' thought that the same dts is used for these devices.

It could be interesting then to have a common dts file and the include per specific device with the little changes they have. I know that the led colors is just a little thing but there is also modded WDR7500 where the flash chip (8 MiB) is changed with the one found in the Archer C7 (16 MiB) and then the LEDE Archer C7 firmware gets flashed showing Archer C7 as model. If there are separated definitions it could be possible to add for example one for that use case showing something like TP-Link WDR7500 (16 MiB mod).
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More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=409#comment1464