[LEDE-DEV] ar71xx use kernel 4.9 by default

[Hauke Mehrtens]

Hi,

I added support for kernel 4.9 to the ar71xx target some days ago and it
was tested by multiple people.

The only regression in kernel 4.9 compared to 4.4, I am aware of was
this performance regression reported by Sven Schönhoff:
http://lists.infradead.org/pipermail/lede-dev/2017-October/009251.html
I haven't found the time to investigate this problem, it would be nice
if some one could look into this.

If there are no other complains I would like to switch the default
kernel of the ar71xx target to 4.9 next weekend, are there any
objections to this plan?

Hauke