Linux 4.7 rc4

It's been a fairly normal week, and rc4 is out. Go test.

The statistics look very normal: about two thirds drivers, with the
rest being half architecture updates and half "misc" (small
ffilesystem updates,. some documentation, and a smattering of patches

The bulk of the driver updates are usb and gpu, but there's iio, leds,
platform drivers, dma etc).

The arch updates are mostly arm, with some small x86 fixlets too.

But it's all pretty small, nothing particularly worrisome.

Shortlog appended for people who want to get a feel for the kinds of
things that have been happening.