Linux 4.11 rc2

As usual, the week after rc1 tends to be fairly quiet when people are
still looking for bugs and taking a breather after the merge window.
But we've got a healthy number of fixes in, and there's some
cleanup/prep patches for the upcoming 5-level page table support that
I took after the merge window just to make the next merge window

There's also a (small) late random driver update.

But most of it is just fixes, with arch and drivers being the bulk of
it (powerpc and i915 stand out, respectively) but with a noticeable
component elsewhere (mm patches mainly through Andrew, some fs
updatres, radix tree test updates etc).

Shortlog appended with details, go forth and test. I think we're in
fine shape for this stage in the development kernel, it shouldn't be
particularly scary to just say "I'll be a bit adventurous and test an
rc2 kernel". Yes, it's early rc time still, but go on, help us make
sure we're doing ok..