Merge tag 'riscv-for-linus-4.20-mw0' into riscv-linux-4.19

RISC-V Patches for the 4.20 Merge Window, Part 1

This patch set contains a lot (at least, for me) of improvements to the
RISC-V kernel port:

* The removal of some cacheinfo values that were bogus.
* On systems with F but without D the kernel will not show the F
  extension to userspace, as it isn't actually supported.
* Support for futexes.
* Removal of some unused code.
* Cleanup of some menuconfig entries.
* Support for systems without a floating-point unit, and for building
  kernels that will never use the floating-point unit.
* More fixes to the RV32I port, which regressed again.  It's really time
  to get this into a regression test somewhere so I stop breaking it.
  Thanks to Zong for resurrecting it again!
* Various fixes that resulted from a year old review of our original
  patch set that I finally got around to.
* Various improvements to SMP support, largely based around having
  switched to logical hart numbering, as well as some interrupt
  improvements.  This one is in the same patch set as above, thanks to
  Atish for sheparding everything though as my patch set was a bit of a
  mess.

I'm pretty sure this is our largest patch set since the original kernel
contribution, and it's certainly the one with the most contributors.
While I don't have anything else I know I'm going to submit for the
merge window, I would be somewhat surprised if I didn't screw anything
up.

Thanks for the help, everyone!