Linux 4.9 rc7

Still on the regular Sunday release schedule, here's rc7.

I think we got all the silly problems I was aware of fixed, and on the
whole things are looking pretty good. In fact, if next week ends up
being very quiet, this _might_ be the last rc, although honestly I
strongly suspect I'll end up doing an rc8. It's been a big release,
and rc7 could have been quieter. We'll see.

I basically reserve the right to make up my mind next weekend.

The changes in rc7 are mainly drivers, architecture and networking. In
fact, most of the driver updates are networking drivers, so I guess I
could say "mostly networking and architecture updates, with a
smattering of other driver updates" (the main other driver areas being
usb, gpu, hid, i2c, iommu). And we've got the usual small random
stuff all over (core kernel, a eBPF fix, some filesystem fixes etc).

The appended shortlog gives a reasonable view into what's up.