[wifi drivers] cherry-pick update from Pivos and revert old drivers adjustments

The following commits:
* Revert adjustments to the old drivers but only touched drivers/amlogic/wifi
* Cherry-Pick the related commits from Pivos tree ( https://github.com/Pivosgroup/buildroot-linux-kernel-m3 ) to update the drivers.

I'm still getting the hangs of git but I thought it better to revert the commits than rebasing as J1nx's fork diverged far away from Pivos and also becuase each of the commits' changes need to be reevaluate.

Benefits:
* rtl81xx_eu driver: rtl8188etv work great
* both rtl81xx_eu and rtl81xx_cu can be enabled the same time (I haven't tested the *cu driver yet)

Next on the agenda
* Test the rtl81xx_cu with rtl8192cu.
* Adjust the wifi drivers, probably disable power saving
* Update the gbox 2.1/2.2 config (I will send a PR soon)


Side notes for the future:
* more descriptive commits
* better commiting: don't include kernel configs and wifi drivers changes in the same commits (compare the partially reverted commits with the originals)
* squashing, squashing and squashing