Pull ARC updates from Vineet Gupta:

 - AXS10x platform clk updates for I2S, PGU

 - add region based cache flush operation for ARCv2 cores

 - enforce PAE40 dependency on HIGHMEM

 - ptrace support for additional regs in ARCv2 cores

 - fix build failure in linux-next dut to a header include ordering
   change

* tag 'arc-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  Revert "ARCv2: Allow enabling PAE40 w/o HIGHMEM"
  ARC: mm: fix build failure in linux-next for UP builds
  ARCv2: ptrace: provide regset for accumulator/r30 regs
  elf: Add ARCv2 specific core note section
  ARCv2: mm: micro-optimize region flush generated code
  ARCv2: mm: Merge 2 updates to DC_CTRL for region flush
  ARCv2: mm: Implement cache region flush operations
  ARC: mm: Move full_page computation into cache version agnostic wrapper
  arc: axs10x: Fix ARC PGU default clock frequency
  arc: axs10x: Add DT bindings for I2S audio playback